A light emitting module includes a lens and first and second light sources aligning with the lens. The lens includes a first biconcave section having a first light-entrance concave surface and a first light-exit concave surface, a second biconcave section having a second light-entrance concave surface and a second light-exit concave surface, and a shared section having a light-exit shared surface. A tangent slope of the shared section where the light-exit shared surface is connected to the first light-exit concave surface is less than a tangent slope of the first biconcave section where the first light-exit concave surface is connected to the light-exit shared surface. A tangent slope of the shared section where the light-exit shared surface is connected to the second light-exit concave surface is larger than a tangent slope of the second biconcave section where the second light-exit concave surface is connected to the light-exit shared surface.