A surface mounted oven controlled crystal oscillator includes a crystal oscillator shell, a crystal oscillation circuit, several functional pins and a base plate. The crystal oscillation circuit is accommodated in a cavity that is formed by the crystal oscillator shell and the base plated and electrically connects with the functional pins. The functional pins drill through the base plate from the cavity. An insulating layer is formed between each functional pin and the base plate. The surface mounted oven controlled crystal oscillator further includes several pads formed at an outer surface of the base plate. The insulating layer is also formed between each pad and the base plate, and the functional pins are electrically connected with the corresponding pads respectively. Added pads, the oven controlled crystal oscillator has high stability, simple manufacturing process, and low manufacturing cost. Moreover, the oven controlled crystal oscillator is mounted on the product by using surface mounted technology, thereby achieving mechanized batch production with high efficiency.