A method for the path synthesis of a planar five-bar mechanism based on wavelet analysis theory is proposed in this paper. Wavelet transform analysis is used to extract wavelet characteristic parameters(WCPs) from the basic dimensional types(BDTs) database. Combined the numerical atlas method with multidimensional search tree, a four dimensions search tree with a depth of five is obtained, in which numbers of leaf nodes are 4,096, and each node stores 59,787 groups of BDTs database numbers. Meanwhile, an index keyword database is established. By comparing the WCPs of a prescribed curve with index keywords, the leaf node where the desired mechanism is located is found. The WCPs of the BDTs in the leaf node are extracted, and a dynamic self-adaptive atlas database is established. Based on the design requirements, the desired mechanism can be obtained by fuzzy identification. Then, a mathematical model is established for calculating the actual sizes of the desired mechanism. The arbitrary design interval path synthesis of a five-bar mechanism is realized. Two examples are presented to demonstrate the veracity and practicality of the method proposed.