EDDHA chelated organic micro-fertilizer and preparation method thereof

The invention provides an EDDHA chelated organic micro-fertilizer and a preparation method thereof. The method comprises the following steps: mixing and heating 150-200g of phenol, 200-500ml of water and 56-112g of potassium hydroxide to 65-75 DEG C; sequentially dropwise adding 50-80ml of ethidene diamine and 200-250ml of 50% glyoxylic acid in a stirring state, and lastingly heating and stirring for 1-2 hours after dropwise adding is ended, so as to obtain a synthetic EDDHA solution; adding microelements to water in a form of a soluble salt in a room-temperature condition, so as to obtain 0.3-0.5mol/L of microelement ionic solution; heating the obtained 400-700ml of EDDHA solution to 65-75 DEG C, adding 100ml of microelement ionic solution in the stirring state, further stirring for 1-2 hours after dropwise adding is ended, and supplementing 200ml of water until the volume reaches 1L, so as to obtain the EDDHA chelated organic micro-fertilizer in a liquid state or a solid state. The EDDHA chelated organic micro-fertilizer provided by the invention is a compound with high stability containing a plurality of microelements, has unique ultrahigh permeability and solubility in water, is not easy to run off, simple in preparation method and applicable to industrial production, and is easily absorbed by plants.