可以使用负lookbehind regex对转义逗号进行转义：

df.show(truncate=False)
+------------------------------------------------------+
|value                                                 |
+------------------------------------------------------+
|value1,value2,value3,value4\,donot split,value5,value6|
+------------------------------------------------------+

df.select(F.split(F.col('value'), "(?<!\\\\),")).show(truncate=False)
+-------------------------------------------------------------+
|split(value, (?<!\\),, -1)                                   |
+-------------------------------------------------------------+
|[value1, value2, value3, value4\,donot split, value5, value6]|
+-------------------------------------------------------------+