diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/MapperUtil.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/MapperUtil.java
index e6dbd342..271d4a62 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/MapperUtil.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/MapperUtil.java
@@ -18,19 +18,111 @@ package com.mybatisflex.core.util;
 import com.mybatisflex.core.BaseMapper;
 import com.mybatisflex.core.field.FieldQuery;
 import com.mybatisflex.core.field.FieldQueryBuilder;
-import com.mybatisflex.core.query.QueryWrapper;
+import com.mybatisflex.core.query.*;
 import org.apache.ibatis.exceptions.TooManyResultsException;
 import org.apache.ibatis.session.defaults.DefaultSqlSession;
 
 import java.util.*;
 import java.util.function.Consumer;
 
+import static com.mybatisflex.core.query.QueryMethods.count;
+
 public class MapperUtil {
 
     private MapperUtil() {
     }
 
 
+    /**
+     * <p>原生的、未经过优化的 COUNT 查询。抛开效率问题不谈，只关注结果的准确性，
+     * 这个 COUNT 查询查出来的分页总数据是 100% 正确的，不接受任何反驳。
+     *
+     * <p>为什么这么说，因为是用子查询实现的，生成的 SQL 如下：
+     *
+     * <p><pre>
+     * {@code
+     * SELECT COUNT(*) AS `total` FROM ( ...用户构建的 SQL 语句... );
+     * }
+     * </pre>
+     *
+     * <p>不进行 SQL 优化的时候，返回的就是这样的 COUNT 查询语句。
+     */
+    public static QueryWrapper rawCountQueryWrapper(QueryWrapper queryWrapper) {
+        return QueryWrapper.create()
+                .select(count().as("total"))
+                .from(queryWrapper);
+    }
+
+    /**
+     * 优化 COUNT 查询语句。
+     */
+    public static QueryWrapper optimizeCountQueryWrapper(QueryWrapper queryWrapper) {
+        List<QueryColumn> selectColumns = CPI.getSelectColumns(queryWrapper);
+        List<QueryColumn> groupByColumns = CPI.getGroupByColumns(queryWrapper);
+        // 如果有 distinct 语句或者 group by 语句则不优化
+        // 这种一旦优化了就会造成 count 语句查询出来的值不对
+        if (hasDistinct(selectColumns) || hasGroupBy(groupByColumns)) {
+            return rawCountQueryWrapper(queryWrapper);
+        }
+        // 判断能不能清除 join 语句
+        if (canClearJoins(queryWrapper)) {
+            CPI.setJoins(queryWrapper, null);
+        }
+        // 最后将最后面的 order by 移除掉
+        // 将 select 里面的列换成 COUNT(*) AS `total` 就好了
+        CPI.setOrderBys(queryWrapper, null);
+        CPI.setSelectColumns(queryWrapper, Collections.singletonList(count().as("total")));
+        return queryWrapper;
+    }
+
+    private static boolean hasDistinct(List<QueryColumn> selectColumns) {
+        if (CollectionUtil.isEmpty(selectColumns)) {
+            return false;
+        }
+        for (QueryColumn selectColumn : selectColumns) {
+            if (selectColumn instanceof DistinctQueryColumn) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static boolean hasGroupBy(List<QueryColumn> groupByColumns) {
+        return CollectionUtil.isNotEmpty(groupByColumns);
+    }
+
+    private static boolean canClearJoins(QueryWrapper queryWrapper) {
+        List<Join> joins = CPI.getJoins(queryWrapper);
+        if (CollectionUtil.isEmpty(joins)) {
+            return false;
+        }
+
+        // 只有全是 left join 语句才会清除 join
+        // 因为如果是 inner join 或 right join 往往都会放大记录数
+        for (Join join : joins) {
+            if (!Join.TYPE_LEFT.equals(CPI.getJoinType(join))) {
+                return false;
+            }
+        }
+
+        // 获取 join 语句中使用到的表名
+        List<String> joinTables = new ArrayList<>();
+//        Map<String, String> joinTables = new HashMap<>();
+        joins.forEach(join -> {
+            QueryTable joinQueryTable = CPI.getJoinQueryTable(join);
+            if (joinQueryTable != null && StringUtil.isNotBlank(joinQueryTable.getName())) {
+                joinTables.add(joinQueryTable.getName());
+            }
+        });
+
+        // 获取 where 语句中的条件
+        QueryCondition where = CPI.getWhereQueryCondition(queryWrapper);
+
+        // 最后判断一下 where 中是否用到了 join 的表
+        return !CPI.containsTable(where, CollectionUtil.toArrayString(joinTables));
+    }
+
+
     @SuppressWarnings({"rawtypes", "unchecked"})
     public static <R> void queryFields(BaseMapper<?> mapper, List<R> list, Consumer<FieldQueryBuilder<R>>[] consumers) {
         if (CollectionUtil.isEmpty(list) || ArrayUtil.isEmpty(consumers) || consumers[0] == null) {