The present disclosure discloses a transparency-based image processing method, device, and terminal. The method includes steps of: acquiring first simulated pixel information representing a first pixel, and acquiring first transparency information; acquiring second simulated pixel information representing a second pixel, and acquiring second transparency information; calculating third simulated pixel information representing a third pixel as a sum of a product of the first simulated pixel information times the first transparency information and a product of the second simulated pixel information times the second transparency information; and acquiring a third actual pixel by narrowing the third simulated pixel information. Compared with an existing fixed-point-number method, the present disclosure reduces prior six integer multiplications and three integer additions to two integer multiplications and one integer addition, such that efficiency in operating the method may be enhanced; compared with an existing method by looking up a table, the transparency-based image processing method provided by the present disclosure does not require traversing any 2D-array table or occupying more memory.