In order to determine the number and depth of grooves in a grooved acetate filter rod,a method based on digital image processing technology was proposed.Aiming at the irregular shape of the end slice of the filter rod,a complementary image fusion algorithm was designed to improve the recognition rate and accuracy of characteristic region.The results indicated that this method completely met the requirements for determination of characteristic parameters of grooved filter rod,the determination accuracy of groove depth was up to 0.01 mm.