The invention provides a backlight source driving method, a driving device and display equipment. The driving method comprises the following steps on each light emitting area: according to the image data of a sub image, the value of a predetermined parameter of each pixel in the sub image is acquired, wherein the image data are data with a first bit number; according to an effective pixel proportion and the value of the predetermined parameter of each pixel, a first reference value, a second reference value, a first proportion and a second proportion are determined; the first reference value is converted to first backlight data with a second bit number, and the second reference value is converted to second backlight data with a second bit number, wherein the second bit number is larger than the first bit number; according to the corresponding relationship between the first proportion and the first backlight data and the corresponding relationship between the second proportion and the second backlight data, target backlight data with the second bit number corresponding to an effective pixel proportion are determined; and according to the target backlight data, driving signals are provided for the light emitting area. The backlight data can be made full use of, and the backlight source can have more grades.