In distributed optical fiber sensing technology, the optical frequency-domain reflectometry (OFDR) has a great advantage in measuring physical quantities such as stress and temperature by virtue of its high spatial resolution and high sensitivity. A set of OFDR distributed sensing system is built by combining weak-reflection fiber grating array, and the visual programming platform is used to realize the collection and processing of data, and ultimately the strain or temperature measurement results at any point in the weak-reflection fiber grating array can be displayed in real time. Experimental results show that the distributed sensing system constructed has a spatial resolution of 0.08 mm, a strain measurement accuracy of 6.9 με, a measurement capability of 1 Hz strain measurement refresh rate, and the ability of distributed dynamic strain monitoring in real time. In petrochemical, aerospace and other fields that require high spatial resolution and real-time dynamic strain sensing capability, the distributed optical fiber strain sensing system developed will have a broad application prospect.