This paper presents the development of superconducting longitudinal gradient bend prototype for Hefei Advanced Light Facility storage ring. The magnet structure parameters were optimized using a developed method that considered the requirements of spatial magnetic field distribution and magnet operating load. To verify the magnet design, a prototype magnet with a longitudinal length of 0.30 m and a pole gap of 46 mm was fabricated using a rectangular niobium-titanium wire and DT4C material. A simple low-temperature test device was built to measure the magnetizing characteristics of the magnet, and after more than 10 times of quench, the maximum operating current of the magnet was measured to be more than 275 A. The longitudinal magnetic field distribution of the magnet was measured, revealing an integral field of 0.4 T·m and a peak magnetic field of approximately 4.5 T at an operating current of about 196 A. The test results are basically consistent with the theoretical design, indicating that the design is reliable.