A channel multiplexing method for reading a detector signal, comprising: step S1: dividing L detector signals into M groups, wherein the number of detectors in each group is greater than or equal to two and less than or equal to N, the number of the detector signals in an a-th group is P(a), and L = ∑ a = 1 M P a, a b-th detector signal in the a-th group is marked as Signal(a,b), and M≥2, N≥2, 1≤a≤M, 1≤b≤N; step S2: dividing an output signal of each of the detectors in step S1 into a row source signal and a column source signal, adding together row source signals of the detectors in the a-th group to form a row signal, and to finally form M row signals for the M groups, adding together the column source signal of a b-th detector in each of the M groups to form a column signal, and to finally form N column signals; step S3: providing a row signal transmission line comprising two signal nodes being a signal node A and a signal node B, connecting the M row signals in step S2 to different positions between the signal node A and the signal node B on the row signal transmission line, marking a difference between a distance from an a-th row signal to the node A and a distance from the a-th row signal to the node B on the row signal transmission line as D_rowx(a), and controlling a value of D_rowx to make values of D_rowx corresponding to any row signals different; step S4: providing a column signal transmission line comprising two signal nodes being a signal node C and a signal node D, connecting the N column signals in step S2 to different positions between the signal node C and the signal node D on the column signal transmission line, marking a difference between a distance from a b-th column signal to the node C and a distance from the b-th column signal to the node D on the column signal transmission line as D_rowy(b), and controlling a value of D_rowy to make values of D_rowy corresponding to any column signals different; and step S5: marking a source detector generating the output signal and acquiring final pulse information based on pulses of four nodes being the node A, the node B, the node C and the node D. step S1: dividing L detector signals into M groups, wherein the number of detectors in each group is greater than or equal to two and less than or equal to N, the number of the detector signals in an a-th group is P(a), and L = ∑ a = 1 M P a, a b-th detector signal in the a-th group is marked as Signal(a,b), and M≥2, N≥2, 1≤a≤M, 1≤b≤N; step S2: dividing an output signal of each of the detectors in step S1 into a row source signal and a column source signal, adding together row source signals of the detectors in the a-th group to form a row signal, and to finally form M row signals for the M groups, adding together the column source signal of a b-th detector in each of the M groups to form a column signal, and to finally form N column signals; step S3: providing a row signal transmission line comprising two signal nodes being a signal node A and a signal node B, connecting the M row signals in step S2 to different positions between the signal node A and the signal node B on the row signal transmission line, marking a difference between a distance from an a-th row signal to the node A and a distance from the a-th row signal to the node B on the row signal transmission line as D_rowx(a), and controlling a value of D_rowx to make values of D_rowx corresponding to any row signals different; step S4: providing a column signal transmission line comprising two signal nodes being a signal node C and a signal node D, connecting the N column signals in step S2 to different positions between the signal node C and the signal node D on the column signal transmission line, marking a difference between a distance from a b-th column signal to the node C and a distance from the b-th column signal to the node D on the column signal transmission line as D_rowy(b), and controlling a value of D_rowy to make values of D_rowy corresponding to any column signals different; and step S5: marking a source detector generating the output signal and acquiring final pulse information based on pulses of four nodes being the node A, the node B, the node C and the node D.