NOVELTY - Chlorine-based gamma -biological nitrogen fertilizer comprises functional component including gamma -polyglutamic acid, wheat straw extract, microbial inoculum and elemental nitrogen, where the gamma -polyglutamic acid and microbial agent are obtained through fermentation process. The wheat straw extract is obtained by extracting tender shoots of wheat straw, the elemental nitrogen is obtained in the form of powder. The elemental nitrogen is urea and ammonium chloride.    USE - Used as chlorine-based gamma -biological nitrogen fertilizer.    ADVANTAGE - The fertilizer: has synergistic effect; improves the nitrogen nutrition efficiency; improves soil micro-environment; promotes nutrient absorption; increases crop yields; and improves plant disease resistance capability.    DETAILED DESCRIPTION - Chlorine-based gamma -biological nitrogen fertilizer comprises functional component including gamma -polyglutamic acid, wheat straw extract, microbial inoculum and elemental nitrogen, where the gamma -polyglutamic acid and microbial agent are obtained through fermentation process. The wheat straw extract is obtained by extracting tender shoots of wheat straw, the elemental nitrogen is obtained in the form of powder. The elemental nitrogen is urea and ammonium chloride. The biological nitrogen fertilizer comprises 0.1-5 pts. wt. gamma -polyglutamic acid, 2-20 pts. wt. wheat straw extract, 3-10 pts. wt. microbial inoculum, and 60-80 pts. wt. urea, and 10-25 pts. wt. ammonium chloride containing 46% elemental nitrogen. An INDEPENDENT CLAIM is also included for preparing the chlorine-based gamma -biological nitrogen fertilizer, comprising (a) crushing material: respectively taking urea and ammonium chloride, crushing, sieving the crushed urea and crushed ammonium chloride until granularity of urea and ammonium chloride is 200-300 meshes, and then dissolving the microbial inoculum into gamma -polyglutamic acid mixed liquid, (b) spraying the gamma -polyglutamic acid mixed liquid on the wheat straw extract by electrostatic spraying method, grinding the mixed material, then mixing with small batch powder, and using a three dimension spatial mixing to prepare mixed powder, (c) taking the mixed powder and urea in a roller mixing machine for mixing, then mixing the resulting mixed powder and ammonium chloride powder by the roller mixer to obtain biological nitrogen fertilizer body, (d) taking the prepared biological fertilizer material, melting the supplemented nitrogen for second time through a high tower and granulating, and sieving to obtain biological fertilizer particle, and (e) packaging: transporting the prepared biological nitrogen fertilizer particles into an automatic packaging machine, metering, and packaging.