Mechanical five-prevention lock

The invention provides a mechanical five-prevention lock. The mechanical five-prevention lock comprises m inlet lines and n outlet lines, wherein the m inlet lines and the n outlet lines are connected through a key in-out device, an mth breaker and an mth earthing switch are sequentially arranged on the mth inlet line, an mth breaker lock plunger lock is arranged on the mth breaker, and an mth switch lock plunger lock is arranged on the mth earthing switch; an nth manhole door lock is arranged on the nth outlet line. In the original state, the mth breaker lock plunger lock is matched with a key Am, a key Bm is coupled to the mth breaker lock plunger lock, n keys C are coupled to the key in-out devices, and a key Dn is coupled to the nth manhole door lock; the key Bm is decoupled through the key Am, the n keys C are synchronously decoupled through m keys B, and the key Dn is decoupled through the key Cn. By means of the mechanical five-prevention lock, right operation procedures of an electrostatic precipitation chamber can be solidified to each operation module, and therefore error operation is accordingly prevented.