Sand screening and crushing device

The utility model provides a sand screening and crushing device. The sand screening and crushing device comprises a box body, a scattering mechanism, a crankshaft, a primary crushing mechanism and a secondary crushing mechanism, a vertically-arranged partition plate is arranged in the middle of the box body and divides the interior of the box body into a primary smashing cavity in the upper portion, a secondary smashing cavity, a first screening cavity and a second screening cavity in the lower portion, wherein the secondary smashing cavity and the first screening cavity are arranged in the middle side by side. A scattering mechanism, a primary crushing mechanism and a guide plate are arranged in the primary crushing cavity; a secondary crushing mechanism is arranged in the secondary crushing cavity, an obliquely-arranged first screening plate is arranged at the top of the first screening cavity, a second connecting rod is connected to the upward-inclined end of the first screening plate, and the second conne