The invention provides a pre-treatment air inlet of a wet dust collector. The pre-treatment air inlet of the wet dust collector comprises an air blower, an air feeding centrifugal pipe and a negative-pressure dust collecting sleeve, wherein the inner part of the air feeding centrifugal pipe communicates with an inner spraying chamber of the wet dust collector; a particle collecting bag is arranged between the inner part of the air feeding centrifugal pipe and the inner spraying chamber of the wet dust collector; a plurality of convex chambers are arranged around an air feeding centrifugal pipe body; an acute angle is formed between the convex direction of each convex chamber and the air flowing direction; a fine hole is formed in an end head of each convex chamber; the negative-pressure dust collecting sleeve sleeves the air feeding centrifugal pipe; a guide pipe which communicates with the inner spraying chamber of the wet dust collector is arranged at one end of the negative-pressure dust collecting sleeve; a negative-pressure air blower and a water tank are sequentially arranged on the guide pipe. With the adoption of the pre-treatment air inlet of the wet dust collector, the problem that the wet dust collector is poor in dust collecting effect under a large particle dust environment, and the particles impact a lot in the wet dust collector, leading to serious influence on the service life of the wet dust collector, can be solved.