A continuous self-calibration and self-alignment method based on attitude angle was proposed for the calibration and initial alignment of floated inertial platform (FLIP) system. According to the working principles of floated platform, the inertial sensor error models were built and the attitude dynamic model for the FLIP was established; in order to make the platform to be rotated in the gravity plane, the torquing policy was designed; using the theory of piece wise constant system (PWCS) and output sensitivity, the observability of system was analyzed. Finally, the proposed method was verified by simulations. The simulation results show that the proposed method can synchronously calibrate and align 42 error coefficients of the FLIP with high accuracy and significantly improve the measurement precision of the system. 