The invention discloses a method for the code division reservation and space division reading of an active radio frequency tag, which pertains to the field of communication technology. In the code division reservation method, a reader firstly utilizes the orthogonality of reserved codes to separate the reserved codes, then uses the separated reserved codes to independently obtain the incident direction of each tag, calculates an antenna array direction vector at^ and channel estimation ht^ corresponding to the tag according to the incident direction of each tag, restructures tag information yt^,compares the restructured tag information yt^ with the original information yt of the tag and chooses tags without reservation collision to send out data; the space division reading method calculates inclined projection operators according to the antenna array direction vector of the tag and then separates the data load of a plurality of tags according to the inclined projection operator of each tag. The method can effectively improve the reading efficiency of the reader as well as provide the position of a target object.