The present invention provides an infrared pixel structure and a hybrid imaging device which use comb-shaped top plates and bottom plates to form capacitors. The upper electrode has a non-fixed end such that the infrared sensitive element in the upper electrode generates thermal stress and deforms when absorbing the infrared light, which changes the capacitance of the capacitors formed by the top plates and the bottom plates to achieve infrared detection and increase the device sensitivity. Furthermore, the infrared pixel structure can be used in an infrared light and visible light hybrid imaging device to achieve visible light imaging and infrared imaging in a same silicon substrate, so as to increase the imaging quality.