This application provides a parameter optimization method for a light-receiving
path system, a light-receiving
path system, and a
lidar. The parameter optimization method includes: determining power characteristic parameters to represent the detection capability of the light-receiving
path system; determining the size parameters of a via based on the power characteristic parameters, according to a preset
spatial distribution of the
light source and the transmit / receive area constraints of the light-receiving path
system; determining the geometry of the via based on preset
stray light suppression conditions; determining whether to install a first
extinction sleeve at the via; and, given that a first
extinction sleeve is installed at the via, determining whether to install a second
extinction sleeve at a rotating reflector. This application, by determining the power characteristic parameters and combining them with the
spatial distribution of the
light source and the transmit / receive area constraints, accurately calculates the optimal size of the via; by combining the
stray light suppression conditions, it derives the geometry of the via and decides whether to install the first and second extinction sleeves, thereby improving the efficiency of the light-receiving path and enabling the
lidar to achieve greater
ranging capability.