The invention discloses special fertilizer for water plants for a shrimp and crab culture pond. The fertilizer is prepared from raw materials in parts by weight as follows: 5-15 parts of monoammonium phosphate, 10-30 parts of urea, 5-20 parts of poly potassium phosphate, 5-15 parts of bentonite, 2-10 parts of pottery clay, 2-8 parts of zeolite powder, 2-10 parts of borax, 5-12 parts of weathered coal, 1-4 parts of nano calcium carbonate, 10-20 parts of molasses powder, 2-12 parts of fish meal, 5-15 parts of fermented cassava, 2-10 parts of chicken manure, 5-15 parts of honey, 0.5-1.5 parts of EDTA (ethylene diamine tetraacetic acid) chelated manganese, 0.5-1.5 parts of diaminoferric xanthohumate and 1-6 parts of an outer-layer coating agent. The fertilizer is environment-friendly, contains very rich nutritional substances, has the good slow-release effect and can meet requirements of the water plants in the whole growth period through one-time fertilizer application.