Marine concrete additive, preparation method therefor and use thereof

A preparation method for a concrete additive for a maritime work environment, comprising:

• S1, compounding a volcanic ash material containing aluminum oxide and lime in proportion to form a mixture, loading the mixture into a sugar coating machine, and spraying alcohol to achieve spherical particles;
• S2, adding the spherical particles in S1 and cement into the sugar coating machine, uniformly spraying deionized water in a rotating process, and coating surface layers of the spherical particles with a layer of cement for maintenance;
• wherein conditions of the maintained in S2 are as follows:
• humidity ranges from 90% to 95%, a temperature ranges from 20° C. to 23° C., and time ranges from 7 days to 14 days,
• and
• S3, placing the maintained particles in S2 into a hydrophobic emulsion, and coating the surface layers of the particles with a layer of hydrophobic emulsion, to obtain a concrete additive.