The invention discloses a high dynamic satellite channel simulator, belonging to the field of satellite communications. The satellite channel simulator comprises a channel parameter generation unit, a channel simulation unit and a radio frequency unit. The whole system has the following working principle: a computer operates satellite channel simulation software, a satellite channel model, a communication frequency point, orbit parameters, terminal parameters and environmental parameters are configured, and a simulation program is started after configuration is completed. In the operating process of the simulation program, generated channel parameters are transmitted to the satellite channel simulation unit via the Ethernet network, the simulation unit loads the satellite channel parameters to a signal sent by a satellite communication device, the realization of channel simulation is completed, and finally, the radio frequency unit modulates the signal to radio frequency. The invention has the main goal of accurately and timely simulating a satellite channel under laboratory conditions, and a channel simulator with controlled cost and strong operability is provided for the development of the satellite communication device.