A centrifugal blower includes a housing (10), a cover (30) arranged on the housing, and an impeller (20) received in a space (25) formed between the housing and the cover. The housing includes a bottom wall (11) and a sidewall (12) surrounding the bottom wall. The sidewall defines an air outlet (121) therein. The sidewall and the impeller cooperatively define an air channel (24) therebetween. The cover includes a main body (31) and a tongue (32) extending from the main body. The tongue is a V-shaped flake and adjacent to the air outlet. The tongue extends into the air channel and protrudes toward the impeller.
