Double three-step phase shifting algorithm (PSA) works well in reducing the measurement error for a digital fringe projection profilometric system. Based on theoretical analysis and experiments, double four-step PSA and double five-step PSA are proposed. In addition, a new method to average two obtained phase maps and to generate the correct phase map is presented, which is simple and effective for double-step PSA. Experiment verifies the correctness of double four-step PSA and double five-step PSA which can reduce much more measurement error than double three-step PSA in the practical applications. The advantages of three-step, four-step and five-step PSA are kept through projecting double the number of fringe patterns which are needed for traditional phase shifting algorithm.