The influence of spatial chirp on broadband ultrashort pulse laser system is analyzed.An experimental method for studying spatial chirp in SG-II-5PW setup with wavefront sensor is proposed.In experiments,the wavefront feature of broadband ultrashort pulse laser is collected after the pulse passing through the stretcher and multi-stage spatial filters,and the lateral spatial chirp and the offset of the wavefront aberration centre relative to the optical axis of the system are measured.The dispersion regulato...