The invention discloses a heart 3D printing system. The system comprises a computer, an ultrasonic diagnostic apparatus, a CT device, an MRI device and a 3D biological printer. The input end of the computer is connected with a similarity comparison module, a physiological recorder and a physiological parameter input module, the output end of the computer is connected with a display module and an image segmentation module, and the image segmentation module is connected with a communication module; the similarity comparison module is connected with a similarity calculation module and a parameterinput module, and the similarity calculation module is connected with a first 3D conversion module, a second 3D conversion module and an ultrasonic memory. According to the invention, three imaging devices are combined to carry out fusion establishment of the three-dimensional graphs on the heart, the imaging precision is improved, and the errors are reduced; during the process of generating a heart 3D model, in order to avoid that the biological cells on the heart 3D model cannot realize synchronous contraction, the blood vessels at the heart part are independently subjected to 3D printing,a clear blood vessel pipeline is provided for a blood pumping function in the later period, and the technical support is provided for improving the synchronous contraction of the biological cells.