The invention provides a reactor analog system and maximum and minimum passive motion capacity test methods thereof. A test device comprises a reactor I and a second loop analog system. Main equipment comprises a reactor analog body, a steam generator, a main circulating pump, a condenser, a heat exchanger, a water feeding pump and a corresponding flow and temperature measuring device. The test methods comprise a loop heating boosting method, a passive operation working condition establishing method, a maximum passive motion capacity test method and a minimum passive motion capacity test method. According to the reactor analog system and maximum and minimum passive motion capacity test methods thereof provided by the invention, a condition that temperature difference of an inlet and outlet of a reactor reaches an allowable maximum value is taken as criterion for maximum passive motion capacity and a condition that steam production errors of two loop steam generators reach a maximum value is taken as criterion for passive motion capacity. The test methods provided by the invention can be used for obtaining maximum and minimum passive motion capacity of a reactor coolant system, so that an application range of a reactor passive operation mode is obtained.