The invention provides a submicron anisotropic samarium iron nitrogen magnet powder and a method for preparing a hybrid bonded magnet therefrom. Samarium-iron alloy is prepared by using a quick setting sheet technology; the samarium-iron alloy is made to perform gas-solid phase reaction in nitrogen or mixed gas of nitrogen and hydrogen to form samarium-iron-nitrogen alloy; then airflow milling and/or ball milling is performed to obtain anisotropic samarium iron nitrogen single-crystal particle magnet powder with a particle size of 0.01-3 [mu]m. Further, the samarium iron nitrogen single-crystal particle magnet powder, as a first ingredient, is mixed with a second ingredient consisting of permanent magnetic ferrite, rapid quenching isotropic neodymium iron boron, anisotropic neodymium iron boron, samarium cobalt and/or neodymium iron nitrogen to form hybrid magnetic powder; processing agents are added; a hybrid bonded magnet is prepared by using a rolling, mould pressing, extrusion or injection method. The prepared samarium iron nitrogen magnet powder are high in magnetic energy product, residual magnetism and intrinsic coercive force, is low in cost and small in particle size; the corresponding hybrid bonded magnet exploits the advantages of different magnetic powder ingredients, is high in shaping degree and mechanical strength and is good in temperature performance.