Wave superposition is a numerical method for calculating sound radiation based on the principle of equivalent source. However, the principle does not indicate definitely how to collocate these equivalent sources. So, it is necessary to evaluate its reconstruction accuracy and analyze the impact factors when wave superposition is applied to sound field reconstruction. The purpose of this study is to find some rules for improving the reconstruction accuracy. A number of impact factors on the precision of sound field reconstruction have been analyzed through theoretical analysis and numerical simulation. It has been proved that the equivalent sources have to be collocated inside of a radiator; moreover, it is best for them to conform to the radiator's shape. However, the measurement plane needs not to conform to the radiator's shape, and even does not need to measure in near-field. In addition, it has been shown that Tikhonov and TSVD regularization method can work well with wave superposition when applied to sound field reconstruction. On the basis of these rules, wave superposition can be used to perform better sound field reconstruction; and also its application range can be extended.