A decoding method for a QR code with one damaged position detection pattern, characterized by comprising the following steps: binarizing a received image containing a QR code pattern and searching for position detection patterns (Q1; Q2); decoding the QR code pattern through the following method if two position detection patterns (Q1; Q2) are searched out; recording the linear equations of the boundaries (Q1.u, Q1.r, Q1.d, Q1.1; Q2.u, Q2.r, Q2.d, Q2.1) of the two position detection patterns (Q1; Q2) and the vertex (Q1.1, Q1.2, Q1.3, Q1.4; Q2.1, Q2.2, Q2.3, Q2.4) coordinates of the two position detection patterns (Q1; Q2) and calculating the data bit width of the QR code pattern; judging whether the two position detection patterns (Q1; Q2) are in an adjacent positional relation or a diagonal positional relation according to the geometrical relation between the boundaries (Q1.u, Q1.r, Q1.d, Q1.1; Q2.u, Q2.r, Q2.d, Q2.1) and the vertexes (Q1.1, Q1.2, Q1.3, Q1.4; Q2.1, Q2.2, Q2.3, Q2.4) of the two position detection patterns (Q1; Q2); searching out a location pattern between the two position detection patterns (Q1; Q2) with the positional relation determined according to the positional relation of the two position detection patterns (Q1; Q2) and the position characteristic and the black and white pattern characteristic of the location pattern; determining the region where the QR code pattern is located according to the two position detection patters (Q1; Q2) and the location pattern; partitioning the region where the QR code pattern is located with grids according to the two position detection patterns (Q1; Q2), the location pattern and the data bit width of the QR code pattern; decoding the QR code pattern partitioned with grids. binarizing a received image containing a QR code pattern and searching for position detection patterns (Q1; Q2); decoding the QR code pattern through the following method if two position detection patterns (Q1; Q2) are searched out; recording the linear equations of the boundaries (Q1.u, Q1.r, Q1.d, Q1.1; Q2.u, Q2.r, Q2.d, Q2.1) of the two position detection patterns (Q1; Q2) and the vertex (Q1.1, Q1.2, Q1.3, Q1.4; Q2.1, Q2.2, Q2.3, Q2.4) coordinates of the two position detection patterns (Q1; Q2) and calculating the data bit width of the QR code pattern; judging whether the two position detection patterns (Q1; Q2) are in an adjacent positional relation or a diagonal positional relation according to the geometrical relation between the boundaries (Q1.u, Q1.r, Q1.d, Q1.1; Q2.u, Q2.r, Q2.d, Q2.1) and the vertexes (Q1.1, Q1.2, Q1.3, Q1.4; Q2.1, Q2.2, Q2.3, Q2.4) of the two position detection patterns (Q1; Q2); searching out a location pattern between the two position detection patterns (Q1; Q2) with the positional relation determined according to the positional relation of the two position detection patterns (Q1; Q2) and the position characteristic and the black and white pattern characteristic of the location pattern; determining the region where the QR code pattern is located according to the two position detection patters (Q1; Q2) and the location pattern; partitioning the region where the QR code pattern is located with grids according to the two position detection patterns (Q1; Q2), the location pattern and the data bit width of the QR code pattern; decoding the QR code pattern partitioned with grids.