The invention provides a hawthorn orchard worst weed botanical inhibitor, relates to herbicide, and particularly relates to a botanical natural inhibitor used for hawthorn orchard worst weeds. The inhibitor is prepared from, by weight, 25 parts of rabdosia rubescens, 30 parts of tussilago farfara, 15 parts of herbs of hokker winghead and 30 parts of akebia stems. The preparation method comprises the steps that the components in the formula are dried to constant weight at 60 DEG C, smashing and even mixing are conducted, 20-mesh sieving is conducted, 75% ethyl alcohol is added according to weight ratio, ultrasonic extraction is conducted for 60 min at 45 DEG C, and extract is obtained after vacuum compression is conducted; water is added to conduct sedimentation, undissolved substances are abandoned, filtrate is obtained, vacuum concentration is conducted to obtain a concentrated solution, spray drying is conducted on the concentrated solution finally, and the inhibitor is obtained. According to the hawthorn orchard worst weed botanical inhibitor, the formula takes natural herbal medicine as source matter, the inhibitor shows high inhibitory activity, the herbicide is high in selectivity, the weeding effect is good, human, livestock and bees are not hurt, pollution to environment does not exist, national degradation can be conducted on the inhibitor through natural microorganisms, attachment to soil does not exist, water quality and air are not affected, and the inhibitor is ecological and safe herbicide.