The invention provides a lens and a light-emitting device. The lens comprises a first lens body, a second lens body and a reflective film. The first lens body is provided with a bottom surface, an incident surface and a circumferential side surface, and the circumferential side surface is a first emergent surface; the incident surface is arranged in the middle, and the second lens body is connected with the top surface of the first lens body; the top surface is a total reflection surface which is in a smooth curved surface shape, and the circumferential side surface is a second emergent surface which is in a smooth curved surface shape; the reflective film is arranged at a central area of the total reflection surface and is used for covering hot spots. Incident light beams are divided into two parts to be emitted, a first part is emitted by the first emergent surface to form a plurality of first emergent light beams, and a second part is reflected by the second lens body, the reflective film and the total reflection surface and then is emitted by the second emergent surface to form a plurality of second emergent light beams; the plurality of first emergent light beams respectively tilt upwards relative to the bottom surface, and the plurality of second emergent light beams respectively tilt downwards relative to the bottom surface. The light-emitting device comprises the lens and an LED (Light Emitting Diode) plane light source.