Method, device, system and medium for testing and purifying test data in test case

The invention provides a method, a device, a system and a medium for testing and purifying test data in a test case, which can be applied to the field of big data or finance. Establishing an input and output mapping table between the input value data set and the preset output value data set; extracting preset function data of the preset output value data set; judging whether the input value data set is missing or not according to a character string rule; when the data is missing, supplementing missing data of the input value data set to obtain input value expansion data; querying the input and output mapping table to obtain preset input data corresponding to the preset function data; calculating the stability of each case to obtain a first proportion and a second proportion; and comparing the similarity to obtain final expansion data to supplement an input value data set of the current test case. The input item and the output item of the test case can be automatically obtained, the data missing area is filled