Microencapsulated soil conditioner (MSC) with water-soluble core and natural polymer shell can be used to solve the problems of soil about over-fertilization and low efficiency. Fulvic acid (FA) is a kind of purified humic acid, which possesses the characteristics of water-solubility, fertilizer maintenance and expedient monitoring. The MSC containing FA was prepared by double emulsion and ion crosslinking methods. Structure analysis revealed that the MSC owned a particle size between 1.58 and 2.14 mm with a similar round shape. Sustained release and biodegradation tests exhibited that MSC can effectively improve the fertilizer-retaining and water-retaining capacities. In addition, a massive amount of these microcapsules were prepared using sharp-hole coagulation bath method. As a type of neutral fertilizer, urea is useful to plant, easy to preserve and use, and has little damage to soil. The two materials, FA and urea, were typical and useful as core materials of MSC for actual applications. The planting experiment of cabbages was carried out using these microcapsules. The growth status of cabbages, physiological activities, nitrogen balance index (NBI) value and photosynthesis rate were investigated. Results demonstrated that the MSC owned the ability of improving the yield of cabbages, and it was a very promising sustained-release fertilizer.