The invention relates to a high-transmittance optical brightness enhancement film. The film comprises a brightness enhancement film body (11), and a microprism structure (12) disposed on the upper surface of the brightness enhancement film body (11), wherein the pitch of the microprism structure is 25 [mu]m to 200 [mu]m. A manufacture apparatus of the film comprises a hot-air machine (2), a feed hopper (3), a hot-air drier (4), an air lock device (5), a hot melt device (6), a pattern roller (8) and a grinding roller (9), wherein the outlet end of the hot melt device (6) is equipped with a calender roller group (7), and the pattern roller (8) and the grinding roller (9) are in cooperation and disposed at the left side of the calender roller group (7). A manufacture process of the film comprises the following steps: S1, pattern roller preparation; S2, material preparing; S3, drying; S4, hot melting of granular materials; S5, calendaring; S6, moulding; and S7, final processing. The advantages are that processing cost is low, the influence on the environment in the manufacture process is small, the manufacture technology is simple, and transmittance is high.