The utility model provides a prefabricated cabin temperature control system, includes air conditioner (1), heater (2), expert fan assembly (3) and temperature control device (4), temperature control device (4) include temperature control unit (41), review for the wetness monitoring sensor (42), temperature sensor (42) passing signal line connection to temperature control unit (41) for the wetness monitoring, directly over air conditioner (1) was installed and is walked before the under -deck screen, trisection arranged the position two air conditioners, and air conditioner controller (11) control end is connected to temperature control unit (41), install in the under -deck lower part heater (2), and the control end of heater control ware (21) is connected to temperature control unit (41), it is connected to temperature control unit (41) including air inlet unit (31), air outlet unit (32), filter screen, the control end that leads to fan assembly controller (33) to lead to fan assembly (3). The utility model discloses alleviate the long -time operating pressure of air conditioner, extension air conditioner life, guarantee under -deck temperature stability.