The invention discloses a low-power device duration of service testing method, and belongs to the device testing technical field; the method comprises the following steps: 1, start testing, and connecting a low power device with a power testing device; 2, reading a static state power Ps, a battery voltage U and a current Is of the low power device in a sleep mode; 3, reading a power Pw and a current Iwi of the low power device in a high frequency working mode; 4, running the low power device in a simulation real environment, adding the power consumed in a time period of the device when a classic state is triggered, thus obtaining the power P of a normal mode within a unit time t; 5, dividing a battery capacity Q of the tested low power device by the normal state power of the unit time, andcalculating the duration of service T of the tested device used in field. The method can accurately measure the running power of the low power device under different running modes in a lab, thus further calculating the duration of service T of the low power device operated in field.