A method for adjusting output ratio of an optic sensor includes the following steps: measuring and obtaining a response spectrum of the optic sensor; analyzing optic response ratios of the response spectrum at different wavelengths; designing a ratio of light reception areas of the optic sensor, the design being carried out in accordance with three aspects of “the response spectrum” “a fixed proportional relationship being present between multiplication of the optic response ratio and the light reception area and an output of light current” and “a proportional relationship being present between the light reception area and the output of the light current”; and obtaining light current outputs of identical proportions (such as 1:1:1) or in a desired ratio (meaning any arbitrary ratio other than 1:1:1, such as 1:2:1, 1:2:3, or 3:4:5) in accordance with the design of the previous step.