diff --git a/kernel/model/export_merge.go b/kernel/model/export_merge.go
index f451f609a..c8b1e503a 100644
--- a/kernel/model/export_merge.go
+++ b/kernel/model/export_merge.go
@@ -20,6 +20,7 @@ import (
 	"github.com/88250/lute/ast"
 	"github.com/88250/lute/parse"
 	"github.com/siyuan-note/siyuan/kernel/filesys"
+	"github.com/siyuan-note/siyuan/kernel/treenode"
 )
 
 func mergeSubDocs(rootTree *parse.Tree) (ret *parse.Tree, err error) {
@@ -30,9 +31,6 @@ func mergeSubDocs(rootTree *parse.Tree) (ret *parse.Tree, err error) {
 	}
 
 	insertPoint := rootTree.Root.LastChild
-	if nil == insertPoint {
-		insertPoint = rootTree.Root
-	}
 
 	// 跳过空段落插入点，向上寻找非空段落
 	for ; nil != insertPoint && ast.NodeParagraph == insertPoint.Type; insertPoint = insertPoint.Previous {
@@ -41,6 +39,17 @@ func mergeSubDocs(rootTree *parse.Tree) (ret *parse.Tree, err error) {
 		}
 	}
 
+	// 导出空文档 Word 和 PDF 时合并子文档失败 https://github.com/siyuan-note/siyuan/issues/7429
+	if nil == insertPoint {
+		// 如果找不到非空段落，则使用第一个段落作为插入点
+		insertPoint = rootTree.Root.FirstChild
+		if nil == insertPoint {
+			// 如果文档为空，则创建一个空段落作为插入点
+			insertPoint = treenode.NewParagraph()
+			rootTree.Root.AppendChild(insertPoint)
+		}
+	}
+
 	for {
 		i := 0
 		if err = walkBlock(insertPoint, rootBlock, i); nil != err {
diff --git a/kernel/model/flashcard.go b/kernel/model/flashcard.go
index 3d118b860..bf6e1214a 100644
--- a/kernel/model/flashcard.go
+++ b/kernel/model/flashcard.go
@@ -249,7 +249,7 @@ func getTreeSubTreeChildBlocks(rootID string) (treeBlockIDs map[string]bool) {
 
 	for _, t := range trees {
 		ast.Walk(t.Root, func(n *ast.Node, entering bool) ast.WalkStatus {
-			if !entering || !n.IsBlock() || ast.NodeDocument == n.Type {
+			if !entering || !n.IsBlock() {
 				return ast.WalkContinue
 			}