The invention discloses a salt mist test box for batteries and a use method of the salt mist test box. A sample table (17) is arranged in a box body (15). A salt mist tube outlet (6) of a salt mist tube (16) right faces the sample table (17), and a salt mist tube inlet (5) of the salt mist tube (16) is provided with a baffle (4). A first air inlet tube (1) right faces the salt mist tube inlet (5) of the salt mist tube (16), a second air inlet tube (2) right faces the baffle (4) and is connected with one end of a salt water inlet tube (3), and the other end of the salt water inlet tube (3) is connected with a salt water pool (14). The box body (15) is provided with a mist discharge tube (17), the mist discharge tube (17) is connected with a salt water return tube (10), and the outer wall of the mist discharge tube (17) is wrapped by a circulating water sleeve (18). The box body (15) is provided with an observation window (13) used for observing the sample table (7). According to the salt mist test box, airflow of a large air compressor is directly introduced, and thus it is unnecessary to specially arrange an air compressor; by the adoption of a V-shaped or U-shaped convective structure, environmental protection is facilitated; the observation window is provided with a wiper, and thus observation is convenient. The salt mist test box has the advantages of being low in cost, good in environmental friendliness, simple in structure, convenient to maintain and the like.