An automatic opening and closing device of door includes a locking unit arranged on the door, a door driving unit configured for driving the door to open or close, a signal receiving unit configured for receiving external or internal signals of the door, and a control unit electrically communicated and connected with the signal receiving unit. The locking unit includes a lock and a power motor. The power motor and the door driving unit are electrically communicated and connected with the control unit. When the signal receiving unit senses a correct door opening signal from the inside or outside of the door, the control unit will first command the power motor to drive the lock to be unlocked and command the door driving unit to act to open the door. After a person has passed the door, the control unit will command the door driving unit to act to close the door and command the power motor to link and drive the lock to be locked. It can be noted that the person does not need to contact any part of the door or the lock, so as to prevent virus infection, which achieves an epidemic prevention effect.