The invention discloses a radio frequency LDMOS device. The radio frequency LDMOS device includes a drain region; a gate oxide layer is arranged above the drain region; the gate oxide layer which is located just above the drain region, is partially removed, so that a window can be formed; a polysilicon plug is arranged on the drain region and the gate oxide layer; a part of the polysilicon plug completely fills the window so as to contact with the drain region; and the other part of the polysilicon plug is located on the gate oxide layer. The radio frequency LDMOS device is characterized in that the doping concentration of the drain region changes gradiently; and in vertical and horizontal directions, the closer the drain region is to a contact portion of the polysilicon plug and the drain region, the higher the doping concentration of the drain region is, and vice versa. The invention also discloses a manufacturing method of the radio frequency LDMOS device. With the radio frequency LDMOS device and the manufacturing method thereof of the invention adopted, the breakdown voltage of the device can be improved, a soft leakage phenomenon can be alleviated, and the output capacitance of the device can be reduced.