Using symbol M-array to produce a one-shot pattern as a projection i mage,a decoding scheme is proposed to solve the symbols encoding for structured light.Firstly,a symbol con tour chain sequence is generated by adopting symbol travel algorithm.According to the chain angle,waveform char acteristics of symbol contour can be expressed.Secondly,based on the symbol′s vector direction and inner ch ain angle,the location and recognition of symbol are accomplished.All symbols can be divided into four cate gories by using symbol vector direction,and each category includes two symbols.According to the waveform cha racteristics of inner chain angle of symbols,the two symbols in each category can be distinguished.Finally,usin g the uniqueness of sub-window in global M-array to generate sub-window positioning conditions,the correspondin g sub-windows can be obtained. The corresponding symbols using the voting algorithm can help to extra ct three-dimensional information of key points of symbol.The experimental results show that the proposed decodin g method can effectively decode symbols,realize the three dimensional reconstruction when it is applied to diff erent detection objects,and has strong robustness.