The invention discloses a rice field non-point source pollution emission reducing and rice yield increasing method, and belongs to the field of biochar agriculture application. According to the scheme, the method comprises the three steps that 1, biochar is applied to the soil surface to form a biochar covering layer; shallow ploughing is conducted on the biochar covering layer; soil is irrigated duly to form a soil-biochar buffer layer. According to the method, the absorption capacity of the biochar to rice filed surface nitrogen is improved, and a green and environment-friendly rice field surface water nitrogen emission reducing method is formed; by changing the biochar application mode, the absorption capacity of the biochar to rice field surface nitrogen can be improved on the conditions that no extra substance input is increased, and external energy is not applied, and then the non-point source pollution risk caused by rice field surface water is reduced.