1. A method for rapidly establishing an indoor wireless signal fingerprint database, comprising the following steps: Step (1): constructing an indoor and outdoor combined three-dimensional spatial structural model of a target scene, wherein the scene comprises an indoor three-dimensional scene of a target building and an outdoor three-dimensional scene around the target building; Step (2): recording and storing information of wireless access device which can be received at the target scene; Step (3): selecting testing points in the indoor of the target building to perform measurement on site and recording the wireless signal fingerprint information that is actually measured at the selected testing points, the wireless signal fingerprint information that is actually measured refers to an identification information and the actual wireless signal strength information of the wireless access device transmitted by the wireless access device in the step (2); Step (4): obtaining theoretical wireless signal fingerprint information of the testing points selected in the step (3), wherein the theoretical wireless signal fingerprint information includes wireless access device labeling information and the theoretical wireless signal intensity information that is obtained through calculation by a propagation model algorithm; Step (5): calibrating parameters of the propagation model depending on difference between the wireless signal intensity information that is actually measured in the step (3) and the wireless signal intensity information that is calculated theoretically in the step (4); Step (6): recalculating the wireless signal intensity information of the wireless access device of the step (2) at the indoor and outdoor combined 3D spatial structural model as described in the step (1) using the calibrated parameters of the propagation model; Step (7): determining number and position of sampling points at a set sampling density on a set horizontal plane within each floor of a building on the basis of floor area of the building space; forming position information of a sampling point, wireless access device labeling information at the position and corresponding wireless signal intensity information data of the sampling point calculated in the step (6) into a data record to be stored in the wireless signal fingerprint database; obtaining wireless signal fingerprint data records of all other sampling points by the same method, to form the wireless signal fingerprint database.