Altitude determination methods of traditional fuze can't act effectively in the environment such as city or mountainous area. According to ineffectiveness of the launch parameter methods of ammunition, an altitude determination method of trajectory discrimination based on turbine alternator was put forward based on actuality of ammunition and fuze. The launch parameter discrimination of mortar bomb adopts turbine alternator of fuze as velocity sensor, and few special velocity information is used to discriminate launch parameters, two cases are included. The experiment result indicates that the discrimination project of mortar bomb launch parameters is feasible, the calculation workload is small, and it could be achieved easily and lays foundation for altitude determination of fuze.