TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (claimed): The organic selenium humic acid fertilizer (I) is prepared by adding celery leaf, stem, or root collected from storage groove into a knife-type crusher via a screw conveyor belt for crushing, adding celery mud into fermentation kettle via a pipeline, adding selenium-enriched yeast and sugar, where the ratio of celery and sugar is 6:4, fermenting for 24 hours at 28 degrees C, stirring for every 2 hours, keeping the pH at 5.5-6.8 to obtain material A i.e. selenium-enriched yeast liquid, taking hyacinth in storage tank, adding into knife-type crusher via a spiral conveyor belt for crushing into slurry, adding into fermentation kettle via a pipeline, adding humic acid and chicken manure, which is first subjected to microwave drying, where the ratio of water hyacinth and chicken manure is 4:6, adding 1% fermentation flora, fermenting for 24 hours, where initial fermentation temperature is 65 degrees C, which is maintained for 6 hours and temperature is maintained at 45-55 degrees C for 0.5 hour, and obtaining chelating agent, collecting garlic from storage tank, adding into a crusher via a spiral conveyor, crushing, adding crushed garlic and chelating agent at 1:1 ratio into the reaction kettle via a conveying pipeline, adding grain vinegar through the conveying belt, conducting acetic acid reaction for 7 days, maintaining the temperature at 32 degrees C to obtain material B, adding materials A and B into neutralization reaction kettle via a pressure pump, where the ratio of selenium-enriched yeast liquid, humic acid, and chelating agent is 20:75:5, reacting for 24 hours at 35 degrees C, stirring for every 0.5 hour, and obtaining the product. The fermentation flora is black Rhizopus, Aspergillus niger, Mucor, A. oryzae, Trichoderma viride, Hansenula, red Streptomyces, yellow Streptomyces, ray fungi, Bacillus subtilis, B. megaterium, B. laterosporus, B. licheniformis, B. thuringiensis, and Acetobacter. The grain vinegar is grain product of Saccharomyces cerevisiae and Acetobacter. ACTIVITY - Fertilizer.