Disclosed are a resistance strain gage (1000) and resistance strain sensor. The resistance strain gage (1000) comprises a flexible substrate (10) and a resistance strain sensing unit (20) attached to the flexible substrate (10), wherein two ends of the resistance strain sensing unit (20) are provided with extraction electrodes (22, 23). The resistance strain sensor comprises the resistance strain gage (1000) and a component under test (2000). The resistance strain gage (1000) and the component under test (2000) are deformed together under the action of a physical quantity. By measuring a variation value of a resistance of the resistance strain gage in the process of deformation to measure the magnitude of the physical quantity applied on the component under test (2000), a maximum strain of 200% and its corresponding physical quantity can be measured with a high integration level, good extendability and easy implementation.