The invention relates to a method used for data calibration in a distributed type optical fiber temperature sensor, which is used for solving the problem of data calibration of DTS. The method comprises the following steps: the first step, receiving original data from the optical fiber in the DTS, wherein the original data comprises S and AS signals, and each signal data comprises a pulse; the second step, respectively calculating the positions of the corresponding pulses of the S and AS signals in the optical fiber by original setting; and the third step, marking an original value again until two pulses are aligned for completing the DTS data calibration, detecting that both the head end and the tail end of the optical fiber are connected to an optical assembly by a data calibration device in the DTS, and transmitting results into the DTS. The marking method based on the original data of the invention can provide more precise calibration and configuration results, so the positioning precision and the spatial resolution of the DTS system can be improved, and in addition, the integral performance of the system can be improved.