The invention discloses an improved micro-electrolysis method and application thereof. The micro-electrolysis method includes the steps that 1, waste water containing organic primary amino compounds is cooled to 0-30 DEG C, and then the pH value is adjusted to 1-3; 2, a nitrite water solution is added into the solution obtained in the step1, and filtering is performed after even mixing; 3, the pH of filtrate obtained in the step2 is adjusted to 2-3, and then iron-carbon micro-electrolysis is performed. In iron-carbon micro-electrolysis, with mother liquor mass being the datum, the amount of added active carbon is 0.1-0.5%, and the amount of added iron powder is 1-4%. Diazotization treatment and iron-carbon micro-electrolysis are used in combination for treating the waste water containing organic primary amino compounds, the effect is good, the chromaticity, COD and NH3-N value of the waste water can be remarkably reduced, advanced treatment for the waste water can be achieved, and resource recycling can be performed on ammonium salt substances in the waste water.