The invention discloses an infrared light reflective and heat-insulating COC plastic, a preparation method and application thereof. The raw material composition of the COC plastic includes: 50wt%-99.5wt% of COC, 0.5wt%-50wt% of infrared reflector, 0-1wt% of antioxidant, 0-1wt% of UV stabilizer, 0-10wt% of titanium dioxide; Agents include Pigment Blue 28, Pigment Blue 36, Pigment Green 50, Pigment Green 60, Pigment Yellow 53, Pigment Brown 24, Pigment Brown 33, Pigment Yellow 164, Pigment Green 17, Pigment Brown 29, Pigment Black 30, Pigment Violet 16, At least one of Pigment Violet 14. The preparation method is as follows: the raw materials are mixed according to the ratio, and then put into a twin-screw extruder through the main feeding port for extrusion, so as to obtain infrared light reflective and heat-insulating COC plastics. When the COC plastic is applied to packaging materials, it can prevent the packaged items from deteriorating due to rapid temperature rise, and is especially suitable for packaging temperature-sensitive components, raw materials and other products.