The present invention discloses a RFID indoor location method. The method comprises: obtaining target location label information and relative angle information sent by a plurality of location readers in the same time period, wherein the relative angle is the corresponding relative angle information when the maximum signal intensity of the emission signals of a target location label is received in the different scanning angles of the location readers in the same time period; according to the relative angle information, employing the location readers to cooperate with the work algorithm to calculate the position information of the target location label; and comprehensively calculating the position where the location label is located through the relative angle information obtained by the location readers located at different positions so as to have high location precision and small location precision influence on the environment changing. The present invention discloses a RFID indoor location device and system and a server, and the beneficial effects mentioned above are provided.