The invention belongs to the technical field of snail grain testing and relates to a solar battery module snail grain testing device and method. The device comprises a high-pressure ageing accelerating testing experimental box and a test piece rack arranged inside the experimental box for bearing test pieces, wherein the test piece rack comprises a cuboid-shaped rack body with a hollow front opening, and at least partition boards horizontally arranged inside the rack body. The method comprises 1, manufacturing a snail grain battery, 2, manufacturing a laminating member, 3, sealing the laminating member, 4, testing the laminating member, and 5, observing snail grains. The solar battery module snail grain testing device and method has the advantages of, 1, greatly shortening the testing period, 2, avoiding the problem of unqualified solar modules due to the snail grains, and 3, being safe, reliable, accurate in evaluation, reasonable in testing period and applicable to being widely applied to predictive testing of snail grains of solar battery modules.