A waterproof apparatus for a terminal side key and a terminal are disclosed. The apparatus includes: a terminal shell (1) with a sidewall hole that is filled with a terminal side key (3), and a terminal side-key circuit board component (2) connected to a terminal mainboard (4), herein, the terminal side-key circuit board component (2) includes: a side-key circuit board (23), an arched metal film (22) fixedly connected to the side-key circuit board, and a circuit board waterproof ring (21) used for wrapping the side-key circuit board (23) and the arched metal film (22) as a whole, herein, the circuit board waterproof ring (21) wrapping the side-key circuit board (23) and the arched metal film (22) as a whole is combined with a sidewall of the terminal shell (1) in an interference-fitted manner. The waterproof apparatus for the terminal side key and the terminal have low costs and high waterproof grades and are simplified in assembly.