This disclosure provides a monitoring auxiliary device and a monitoring system. The monitoring auxiliary device is in wired connection with multiple types of sensors to obtain physiological parameter signals detected by the sensors. The monitoring auxiliary device outputs monitoring-related data in a wired manner. When not in wired connection with the monitor, the monitoring-related data is transmitted to a monitor through a wireless communication module. The monitoring auxiliary device summarizes data from various sensors and outputs said data to the monitor in a wired manner or a wireless manner, requiring very few cables to connect with the monitor, thereby reducing a workload of medical staff plugging and unplugging cables and maintaining a clean surface of patient support.