A turbine type pulse generator for downhole drilling tool has a pulse generating device (2), which has a turbine housing (21), a turbine shaft (22) concentrically arranged inside the turbine housing (21), a turbine mechanism arranged around the turbine shaft (22), and a valve disc mechanism provided at a lower end of the turbine shaft (22). The turbine mechanism is configured to drive the turbine shaft (22) to rotate under an impact of drilling fluid, so that a flow area of the valve disc mechanism is changed periodically to generate pressure pulses. The turbine type pulse generator also has an automatic control mechanism (1) configured to keep the turbine shaft (22) static relative to the turbine housing (21) in a circumferential direction during composite drilling, and to drive the turbine shaft (22) to rotate relative to the turbine housing (21) under an impact of the turbine mechanism during sliding drilling.