Sample is an important basic material for identification, and its quality affects the quality of identification opinions to a great extent. Based on the identification of 100 cases of seal seal seal, It is found that there are some non-standard samples in the current seal seal identification practice, which is reflected in the nature, quantity and state of samples. The reasons are both the absence of the system and the bias of the relevant subjects in cognition. Then the solutions are put forward. Firstly, the reference catalogue of seal seal identification sample materials should be established to standardize the sample materials from the system level. Secondly, give full play to the active role of judicial and technical personnel, and do a good job in the quality control of external entrusted authentication work; Thirdly, strictly abide by the threshold of access to judicial expertise, and further promote the standardization of sample materials.