The invention relates to a user mouse behavior synthesis and simulation method and system. The method comprises (1), a data collection and processing step of collecting original mouse data of a user in real time, segmenting and cleaning the data, and storing the data to a history operation database; (2), a model training step of for operation without movement, training a truncated normal distribution model, generating a time interval parameter, for the operation with the movement, extracting a clustering characteristic and a matching characteristic, and establishing a training set; and (3), anoperation synthesis and simulation step of for the operation without the movement, establishing a message sequence of simulation operation through utilization of the truncated normal distribution model, for the operation with the movement, matching out a sample as a template through utilization of a clustering model and a classification model, and synthesizing a synthesized operation sequence consistent with a requirement parameter of to-be-simulated operation. The method and the system pass an identity authentication model established based on the operation according to a success rate of 70%, wherein the identity authentication model is realized according to literature in the prior art.