The invention relates to the technical field of field emission display, in particular to a field emission display module for a super-large spliced display screen and a preparation method thereof. The field emission display module comprises an anode glass substrate, a cathode glass substrate, sealing edges, fluorescence powder, isolators and a cathode transmitter, and is characterized in that the anode glass substrate and the cathode glass substrate are arranged in parallel up and down; the isolators which are arranged in grid shape are arranged between the anode glass substrate and the cathode glass substrate; and sealing edges with width of 1/2 pixel space are reserved on the left side edge and the right side edge of the anode glass substrate and the cathode glass substrate. Compared with the prior art, the preparation process is simpler than LED by adopting a thick film process with low cost, the device follows the process of a vacuum fluorescent display tube with investment and manufacturing cost far lower than the LED; and the spliced large screen based on the field emission display unit module has the advantages of low manufacture cost, high brightness, good stability, long service life, low power consumption, high response speed, full color display, good compatibility to environment and the like.