The invention provides a trackless measurement construction method for the inner ring network of a subway tunnel, belonging to the technical field of subway construction, comprising step 1, determining the starting measurement mileage and calculating the coordinates of the starting measurement point, and step 2, calculating the starting measurement point and every preset distance The design rail surface elevation of the corresponding point of N2, step 3, the positioning mark of the design rail surface elevation position of the starting point, step 4, the starting point is the starting point, and the design rail surface elevation measurement mark of the corresponding point every preset distance N2 , step five, the total station measures the slope distance in the shield tunnel, and takes the average value, step six, determines the installation height position of the ring network support, and step seven, checks and checks during the measurement process. Adopting the trackless measurement construction method of the inner ring network of the subway tunnel, the entry time is greatly advanced, and the height measurement construction of the bracket installation can be carried out before the track laying construction, which reduces the pressure of the construction period for the subsequent process, reduces the interference of cross construction, and improves the construction efficiency. .