The invention relates to a multifunctional photoelectric detection instrument and a target position observing and determining method implemented by the same. The multifunctional photoelectric detection instrument comprises refrigerating infrared sensors, a laser range finder, a visible light channel, a GPS (global positioning system) module, a magnetic compass, a comprehensive information processing unit, a power module and a control panel, the comprehensive information processing unit is respectively connected with the refrigerating infrared sensors, the laser range finder, the GPS module, the magnetic compass, the display module and the control panel, and the visible light channel is connected onto the laser range finder. The method includes methods for observing a target via the visible light channel, a method for observing the target and determining target direction via the refrigerating infrared sensor and a method for automatically solving coordinates of the target position. The multifunctional photoelectric detection instrument and the target position observing and determining method have the advantages that the target is detected and positioned by a single person, and images, the direction, the distance and position information of the target are accurately provided in real time. Besides, the various sensors are integrated, a miniaturization design is adopted, portability is high, and single-person detection capacity and information acquisition capacity are improved.