What is the principle of Mach rushing to the missile when Falcon Brigade rescued Wu?

Don't take TV plays seriously. I haven't seen this movie full of jokes, but I can tell you roughly what will happen if J 10 really attacks the pirate ship:

The missile launched by the pirate ship must be an air defense missile, which is nothing more than an infrared or ultraviolet dual-mode guidance head. The old model has no infrared gaze ability, and it can also use a stronger heat source to trick the missile into unlocking; If the plane is locked by this missile, it can be taken away by throwing jamming bombs or using another plane with higher speed to relay the missile, which is closer to what you said. The principle is that the aircraft that lures the missile has a stronger thermal signal, which can take the missile away, but the bait should be unlocked when luring the missile away, which requires the bait to maintain a state of high maneuverability and high energy, and finally achieve the purpose of unlocking by luring the missile to turn and consuming the energy of the missile. But the probability of being shot down is very high, unless there is no way, no one will play like that, because missiles are far more mobile than airplanes, so you can only see this in TV dramas.

Newer infrared or ultraviolet homing air defense missiles have infrared staring arrays. At this time, the missile is not aiming at a heat source, but at the thermal image of the target aircraft engine. Once the missile is locked, it can't get rid of flying to the sun or throwing jamming bombs. This kind of play is naturally useless, because the spectral images are different, and the missile will not be fooled. In case the proximity fuse explodes, both planes may die.

Things in TV plays are not credible, and it is impossible to do so in conventional air combat, because the plane can pre-emptively hit the missile shooter who has not yet been launched by virtue of its better maneuverability than the ship, and the pilot will choose a reasonable entry angle, or the snake maneuver will make the other side unable to aim, or throw a lot of jamming bombs before the attack, which will interfere with the shooter's aiming, while the surprise attack of the jet plane is only a matter of an instant, and the chance of catching up with the plane after the separate attack is very small. Moreover, the plane does not need to attack the ship, and a missile can blow the whole ship to pieces outside the range of air defense missiles.

In short, don't take this joke seriously.