Rolling Rocket/Shell (RR/S) can effectively overcome the impact point error caused by the asymmetry of aerodynamic appearance and mass eccentricity .etc. The spatial attitude of RR/S in the process of flight must be studied for that RR/S realizes the guidance control and improves the falling point precision. This paper introduces a semi physical simulation of RR/S attitude algorithm based on non-holonomic Inertial Measurement Unit (IMU) which is composed of 3 orthogonal import rate gyroscopes. It adopts the 902E-1 two-axis turntable to simulate the spatial attitude of RR/S, and uses the non-holonomic IMU, which is fixed on the turntable by ensuring the axes of them to be aimed, to measure the 3-axis angular rate motion of the turntable. By setting the motion condition of the turntable, we can get the 3-axis angular rate data of the IMU and the 3-axis angular position data of the turntable. The attitude algorithm simulation of IMU adopts the four-sample rotation vector algorithm based on MTLAB/Simulink. The simulation results show that the semi-physical simulation method can model the spatial attitude of RR/S truly and provide exact and real-time attitude information of RR/S which is rolling in the two-axis complex movement condition.