The essence of NAND gate is the superposition of AND gate and NOT gate. The AND gate operation is performed first, and then the NOT gate is performed. It is the basis of the DNA computer. In order to realize the computing of NAND gate, a NAND gate computational model is established based on the DNA origami template. The inputs of the logic value are completed by the Hybridization Chain Reaction (HCR) on the DNA origami template. The input strands first react with the AND gate region and then react with the NOT gate region. The result of the reaction is shown by dynamically separation of the gold nanoparticles on the DNA origami template. The simulation of the model through Visual DSD shows that the system has the advantages of high feasibility.