The invention discloses a method for automatically identifying the position of temperature sensors in an air source water heater. The method comprises the following steps that by adopting the combination of a controller, a non-volatile memory, a relay drive circuit, the three temperature sensors and a clock circuit, the controller obtains initial temperature values of the three temperature sensorswhen the water heater starts heating, and then the controller obtains the real-time temperature value when the water heater heats for two minutes; and the controller enables the real-time temperaturevalue and the initial temperature of the three temperature sensors to make a comparison, and then according to the comparative result, the three temperature sensors are determined to correspond to awater tank temperature sensor, a coiled pipe temperature sensor and an air exhaust temperature sensor. According to the method for automatically identifying the position of the temperature sensors inthe air source water heater, when the water tank temperature sensor, the coiled pipe temperature sensor and the air exhaust temperature sensor are connected with the controller, wire connection terminals of the controller does not need to be distinguished, the controller can identify automatically, and thus not only can workers install initially, maintain or replace the temperature sensors conveniently, but also the normal operation of the air source heat pump water heater can be guaranteed.