Since 2016, The Korea Advanced Institute of Science and Technology (KAIST) rocket laboratory has conducted lab-scale sounding rocket development and flight test using 250 N class hydrogen peroxide hybrid rocket. Several flight tests have confirmed that the rocket can reach an altitude of 100 m. Based on the successful flight test results, KAIST rocket laboratory started to develop a hydrogen peroxide hybrid rocket capable of reaching an altitude of 3 km. The thrust level of the hybrid rocket was determined through the calculation of the required thrust to reach the altitude of 3 km. The multi-port solid fuel was designed and applied to ensure light weight and miniaturization of the rocket. A dome manifold was also designed to prevent water hammering due to increased oxidizer mass flow rate and feeding pressure. Through a hot-fire test, characteristic velocity and thrust were confirmed to reach values of over 90 %; also, the measured O/F was close to the design value.