Puncture is a widely used surgical technique in medicine that plays a crucial role in cancer treatment. Traditional puncture surgeries require the collaboration of multiple surgeons, and the success rate relies heavily on their experience and skills. Robot technology can overcome the limitations of manual puncture effectively by improving operational accuracy and stability. This has made puncture robots a key area of focus in the field of medical robotics. In this paper, the design of a 4-Degree-of-Freedom (DOF) wearable assisted puncture robot is proposed. The robot consists of two distinct mechanisms: a position adjustment mechanism and an angle adjustment mechanism. These two mechanisms enable the planar movement of two center blocks, and translate it into the translation and pitch of the puncture needle. Kinematic analysis of the designed robot mechanism is conducted and establishes the relationship between the inputs and the outputs. Based on this proposed robot design, a prototype was manufactured that achieves the original design goals of being lightweight (0.44 kg) and compact (170 mm × 170 mm × 72 mm). The prototype can adjust the position, yaw angle and pitch angle of the puncture needle cannula. The puncture operation can then be performed by passing the needle through the cannula.