When increasing the dataframe, the table becomes empty, how to solve this problem?

Question

big data

Often you need to parse an embedded json file using pyspark. And when it needs to be done with a small file, then everything works well, but when you need to parse a large file, then in the process of increasing the dataframe, the dataframe simply becomes empty, but printSchema() everything works, and you can see the structure of the dataframe, but the data is just where then disappear. How to solve this problem?