The invention discloses a method for preparing oriented porous silicon nitride ceramics based on a gelatin solution freeze-drying technology. Silicon nitride powder mixed with a sintering addition agent, and a gelatin solution at certain concentration are mixed to form a uniform system, then vacuum bubble removing is carried out, and the mixture is cooled under the temperature of 1-20 DEG C to be promoted to be gelatinized to obtain colloid; the colloid is frozen at the temperature of minus 90-minus 10 DEG C, low-temperature vacuum drying is carried out to obtain a green body, the green body is sintered under the nitrogen atmosphere after gelatin discharging is carried out, and finally the oriented porous silicon nitride ceramics is obtained. According to the method for preparing the oriented porous silicon nitride ceramics based on the gelatin solution freeze-drying technology, the features that a gelcasting blank is high in strength and by means of a freeze-drying method, hole gaps are evenly distributed, the orientation degree is superior, and the hole communication performance is good are combined, and the gelatin superior in the water storage capability is used for being prepared into the gelatin solution to be mixed with the silicon nitride powder to prepare the oriented porous silicon nitride ceramics for the first time.