The work aims to realize the control on dot gain of metal cans by laser direct engraving 3D dot plate making. With aluminum can as the printing material, plate making and printing were carried out by changing the parameters such as the shape of 3D dot, capping and engraving side peak angle. The dot gain of printed products was measured and analyzed to determine the best plate making parameters. The performance of rounded square dot in the middle tone was better than that of round dot, and the reduction effect of "capped was better than that of "un-capped dot with engraving side peak angle of 80° was smaller than that of dot with engraving side peak angle of 50°. When the number of screening lines and screening angle are determined, it is suggested to select rounded square "capped dots with large engraving side peak angle, which is conducive to improving the dot gain of metal cans in actual production.