Abstract: Advanced radiotherapy technology enables the dose to more accurately conform to the tumor target area of the patient, providing accurate treatment for the patient, but the gradient of the patient’s radiation dose at the tumor edge is getting larger, which putting forward higher requirements for radiotherapy dose verification. The dose verification system software KylinRay-Dose4D can verify the patient’s pre-treatment plan and the in vivo/on-line dose during the patient’s treatment, providing important reference for the physicist to modify the radiotherapy plan and ensuring that the patient receives accurate treatment. This study introduces the overall design and key technologies of KylinRay-Dose4D, and tests the pre-treatment plan dose checking calculation and 2D/3D dose verification through clinical cases. The test results showed that the 2D/3D gamma pass rate (3 mm/3%) of KylinRay-Dose4D reconstructed dose compared with TPS plan dose and measured dose is larger than 95%, which indicating that the reconstructed dose of KylinRay-Dose4D meets the requirement of clinical application.