The invention relates to the technical field of leather making techniques and provides a wet-state dyeing finishing and fixation method for leathers based on a zirconium-aluminum-titanium complex. The zirconium-aluminum-titanium complex is added in a later period of dyeing and fat-liquoring; the zirconium-aluminum-titanium complex is a multi-metal cation tanning agent which may combine with leather fibers so as to increase positive charge on leather surface, to improve tinting strength of the leather surface and color brightness and to basically solve the shading problem, color fullness of cationic crust leathers is improved, consumption of dyes and formic acid in traditional fixation methods is lowered, dyeing rate and fastness of dyes are increased, the content of dyes in spent dye liquor is further decreased, wastewater treatment is easier, and a leather making process is greener.