Compound with high algae removal activity and preparation method thereof

The invention relates to an algae-removal compound, and provides a compound with high algae removal activity, a preparation method thereof and application in the preparation of an algaecide. A production strain of the compound with the high algae removal activity is Pseudoalteromonas sp.SP48 which has the molecular formula of C12H10N4O2 and is called dimethylpyrimidine. The preparation method comprises the following steps of: scribing a flat plate to separately culture the SP48 on the flat plate, inoculating single colonies into a culture medium for fermentation, performing centrifugation, collecting supernate, performing extraction with ethyl acetate to obtain ethyl acetate crude extract, performing chromatography on the ethyl acetate crude extract in a way of taking methanol as an eluent to sequentially obtain three components E1, E2 and E3, and performing the chromatography on the component E3 by a Sephadex LH-20 gel column in a way of taking acetone as the eluent to sequentially obtain the three components E3-1, E3-2 and E3-3, wherein the E3-3 is the product.