diff --git a/contributors/bob-zhao/pdf2imgs.py b/contributors/bob-zhao/pdf2imgs.py
new file mode 100644
index 0000000000000000000000000000000000000000..9827e94d1435d7094458e28bd149a78031d2f9da
--- /dev/null
+++ b/contributors/bob-zhao/pdf2imgs.py
@@ -0,0 +1,32 @@
+import os
+from pdf2image import convert_from_path
+
+def pdf2imgs(pdf_path:str, out_dir=".") -> None:
+    """to change the pdf file to a folder of images
+
+    Args:
+        pdf_path (str): the pdf file path,
+        out_dir (str, optional): the output dir. Defaults to ".".
+
+    Raises:
+        ValueError: the pdf_path not available
+
+    Example:
+        >>> pdf2imgs("test.pdf", "./test")
+    """
+
+    assert isinstance(pdf_path, str), "pdf_path must be str"
+    assert isinstance(out_dir, str), "out_dir must be str"
+
+    pdf_name = pdf_path[pdf_path.rfind("/")+1:pdf_path.rfind(".")]
+    out_dir = os.path.join(out_dir, pdf_name)
+
+    if not os.path.exists(out_dir): 
+        os.makedirs(out_dir)
+
+    if not (pdf_path.endswith("pdf") or pdf_path.endswith("ai")):
+        raise ValueError("file must end with .pdf or .ai") 
+
+    images = convert_from_path(pdf_path)
+    for i, img in  enumerate(images):
+        img.save(os.path.join(out_dir, f"page{i}.jpg"))
diff --git a/contributors/bob-zhao/requirements.txt b/contributors/bob-zhao/requirements.txt
new file mode 100644
index 0000000000000000000000000000000000000000..c44275a9fef81062fbc4b27f7b59cd183749eeba
--- /dev/null
+++ b/contributors/bob-zhao/requirements.txt
@@ -0,0 +1 @@
+pdf2image=1.16.0
\ No newline at end of file
diff --git a/contributors/bob-zhao/test.py b/contributors/bob-zhao/test.py
new file mode 100644
index 0000000000000000000000000000000000000000..c97cd86e4fead4cf85640cc2e114dea2952487a3
--- /dev/null
+++ b/contributors/bob-zhao/test.py
@@ -0,0 +1,4 @@
+from pdf2imgs import pdf2imgs
+
+pdf2imgs("word2vec.pdf", "./testfile")
+
diff --git a/contributors/bob-zhao/word2vec.pdf b/contributors/bob-zhao/word2vec.pdf
new file mode 100644
index 0000000000000000000000000000000000000000..c7bf771632081c4f27f736ecbab529558a844da8
Binary files /dev/null and b/contributors/bob-zhao/word2vec.pdf differ