It is an enlarged and improved version according to MIG 21 series. Aerodynamic aspect: reduced sweep angle. In addition, the side strip wing is added to optimize the aerodynamic characteristic range, reduce the turning radius and speed up the nose directivity. The surface of the fuselage is sprayed with a low detectable absorbing coating containing nickel, manganese and other materials. Now its radar reflection cross-sectional area is less than 1 square meter.; Weapons: the electronic scanning phase radar is used in the nose radome, with an effective detection range of 150 kilometers. Upgrade the fire control system to match the medium and long-range air-to-air missiles, with the function of no matter after firing.; Flight control and Avionics: the use of differential flat tail increases the roll maneuver characteristics. And a set of red / ultraviolet search and tracking equipment is added under the nose. Now it can detect stealth targets, and its effective detection range for stealth targets is 50 kilometers.