An inertial sensing device comprising a circuit board provided with an inertial sensor. The inertial sensing device also comprises a base, a rotating plate and a power source assembly. The circuit board is mounted on the rotating plate, the power source assembly is mounted on the base, the rotating plate is drivingly connected to a power output shaft of the power source assembly. The circuit board rotates along with the rotating plate in a reciprocating or a continuous manner at a speed of 1 to 200 RPM. The inertial sensing device is combined with a monitored movable target under operating conditions, and transmits a collected signal to a personal navigation system to display an instantaneous geographic position of the target. The inertial sensing device is low in cost, small in size, and is capable of controlling the heading error within 1°/hour to increase the accuracy of indoor navigation systems.