Embodiments of the present invention provide a positioning method, a positioning server, and a positioning system. The positioning method includes: separately obtaining, by a positioning server, location coordinates of M positioning nodes; separately obtaining, by the positioning server, a reference signal time difference RSTD between an ith positioning node and an (i+1)th positioning node in the M positioning nodes and a jth mobile terminal in two mobile terminals; determining, by the positioning server, a relative RSTD according to the RSTD; and determining, by the positioning server, location coordinates of the two mobile terminals according to the relative RSTD and the location coordinates of the M positioning nodes.