A bioprinter spray head assembly, comprising a mounting block having a passage and a spray head mounted in the passage , wherein a first flow channel is provided in the mounting block , one end of the first flow channel is provided with a port communicating with the passage ; the spray head comprises an equal diameter portion away from an outlet of the passage and a reduced diameter portion close to the outlet of the passage , wherein a second flow channel is formed between the reduced diameter portion and the passage , an opening is formed between the reduced diameter portion and the port to communicate the first flow channel and the second flow channel , and the equal diameter portion is configured to occlude the port , the spray head comprising a third flow channel which is configured to communicate with the outlet of the spray head ; characterized in that the bioprinter spray head assembly comprises a spray head groups comprising a plurality of alternative spray heads, wherein, each of the plurality of alternative sprayer heads is provided with corresponding equal diameter portion and reduced diameter portion having lengths different from the same of other alternative sprayer heads, and the spray head is selected from the plurality of alternative spray heads to achieve one of the following states: a fully occluded state: in the fully occluded state, the equal diameter portion completely occludes the port ; a partially occluded state: in the partially occluded state, the equal diameter portion partially occludes the port ; a fully open state: in the fully open state, the port fully faces the reduced diameter portion ; or the spray head is movable in the passage , for adjusting a position of the reduced diameter portion relative to the port of the first flow channel to achieve one of the following states: a fully occluded state: in the fully occluded state, the equal diameter portion completely occludes the port ; a partially occluded state: in the partially occluded state, the equal diameter portion partially occludes the port ; a fully open state: in the fully open state, the port fully faces the reduced diameter portion . a fully occluded state: in the fully occluded state, the equal diameter portion completely occludes the port ; a partially occluded state: in the partially occluded state, the equal diameter portion partially occludes the port ; a fully open state: in the fully open state, the port fully faces the reduced diameter portion ; or the spray head is movable in the passage , for adjusting a position of the reduced diameter portion relative to the port of the first flow channel to achieve one of the following states: a fully occluded state: in the fully occluded state, the equal diameter portion completely occludes the port ; a partially occluded state: in the partially occluded state, the equal diameter portion partially occludes the port ; a fully open state: in the fully open state, the port fully faces the reduced diameter portion . a fully occluded state: in the fully occluded state, the equal diameter portion completely occludes the port ; a partially occluded state: in the partially occluded state, the equal diameter portion partially occludes the port ; a fully open state: in the fully open state, the port fully faces the reduced diameter portion . <EOS>