The utility model discloses a wireless terminal testing device and a wireless terminal testing system. The wireless terminal testing device, i.e. the testing port expansion device (1) comprises a control unit (11), a communication interface change-over switch (12), a power change-over switch (13) and a testing signal change-over switch (14). The control unit (11) of the testing port expansion device (1) is used for receiving a switching control instruction sent by a master control device (2) in the wireless terminal testing system, and switching instructions are sent to the communication interface change-over switch (12), the power change-over switch (13) and the testing signal change-over switch (14) based on the switching control instruction. The power change-over switch (13), the testing signal change-over switch (14) and the communication interface change-over switch (12) of the testing port expansion device (1) are all used for controlling N paths of terminals to be switched between on and off states based on the switching instructions. According to the above device, the efficiency of a wireless terminal test is improved and waste of resources is minimized.