The invention discloses a simulation device capable of simulating asphalt pavement ruts in longitudinal slope conditions. The simulation device comprises two parts including a rut test machine and a test mold. An electromotor of the rut test machine is a variable-frequency electromotor. The traveling speed of test wheels can be controlled through control of the rotate speed of the variable-frequency electromotor by use of a frequency changer, and the traveling speed of the test wheels can be randomly adjusted between 10 times/min (one-way)-60 times/min (one-way). The test mold comprises, from bottom to top, a slope cushion block (15), a test mold baseplate (17) and a test mold sidewall (18). Through use of the simulation device, the traveling speed of the test wheels can be controlled through control of the rotate speed of the variable-frequency electromotor through use of the frequency changer; route longitudinal slope can be simulated through use of the rut test mold provided with the slope cushion block , and longitudinal slope size can be realized through change of the slope angle alpha of the slope cushion block; and the simulation device can simultaneously simulate influences of both vehicle speed and the longitudinal slope on the ruts, so that action modes of wheel load are more in accordance with actual action modes in the longitudinal slope conditions and generated rut test results are more in accordance with actual situations.