The invention relates to the medical slice imaging and nuclear-imaging field, in particular to a first-group board card, a signal buffering unit, a second-group receiving board card, a data buffering unit, a reference clock 17, a clock adjusting unit and an on-site programmable gate array that are used for a conforming system in a positron slice scanning device; the method is characterized in that the on-site programmable gate array is utilized to judge the time, the position and the energy among all matters, and two matters that pass through the judging and selecting regulations form a conforming case. By inducting the on-site programmable gate array, the case information captured by a front-end detector module of a PET apparatus can be processed fast and high-efficiently by compiling hardware description language, so as to ensure whether the conforming matters happen or not. The method is an improvement of the process of the prior PET conforming system. The method can finish the process of the conforming system high-efficiently and fast by using a piece of FPGA and can lead the system not to be inducted into the dead time while the high system sensitivity is obtained.