The utility model provides a novel go out water thermostat base, belongs to engine festival temperature field. Warm braw filler neck and tiny loop filler neck all fixed mounting be in the left side of thermostat base casing, thermostat base rubber ring fixed mounting at the lower extreme of thermostat base casing, water temperature sensor set up the right side at the thermostat base casing, temperature saver cover through screw fixed mounting on the right side of thermostat base casing, and the internal spatial structure of temperature saver cover and water temperature sensor's appearance phase -match, water temperature sensor's fixed the penetrating in mounting hole deepening to the thermostat base casing of thermostat base casing of sense terminal. The utility model provides a novel go out water thermostat base, structural design is equitable, compact, under guaranteeing that temperature saver wax -wrapped pill and water temperature sensor can the prerequisites of accurate perception temperature, for the cooling system tiny loop has increased by one protection design, simultaneously the effective control the whole size of engine, improved space utilization, it is easier to mate the motorcycle type.