The purpose of the present invention is to provide a natural pesticide composition which reduces environmental damage, is harmless to the human body and has excellent insecticidal activity, and a preparation method of the natural pesticide composition. The natural pesticide composition according to the present invention comprises: 30-70 wt% of a first insecticidal ingredient which is prepared by adding 300-600 parts by weight of chloroform, a lower alcohol, or a mixture thereof to 10-20 parts by weight of Sophora flavescens root, 5-10 parts by weight of Acorus calamus L. and 5-10 parts by weight of Sasa borealis leaves, extracting and concentrating the resultant product for 5-24 hours to obtain a concentrate, inoculating 3-5 parts by weight of a Bacillus thuringiensis strain into the concentrate, and culturing the concentrate having Bacillus thuringiensis strain inoculated thereinto； and 30-70 wt% of a second insecticidal ingredient which is prepared by adding 300-600 parts by weight of water to 10-20 parts by weight of Canavalia gladiate, 2-5 parts by weight of Tremella fuciformis and 5-10 parts by weight of Epimedium koreanum Nakai, performing hot water extraction and concentration of the mixture to obtain a concentrate, inoculating 3-5 parts by weight of a Bacillus subtilis strain into the concentrate, and culturing the concentrate having Bacillus subtilis strain inoculated thereinto.본 발명은 고삼 뿌리 10~20 중량부, 창포 5~10 중량부, 및 조릿대잎 5~10 중량부에 클로로포름, 저급알코올 또는 이들의 혼합물 300~600 중량부를 가하여 5~24시간 동안 추출 및 농축하고, 상기 농축액에 바실러스 투린지엔시스(Bacillus thuringiensis) 균주를 3~5 중량부를 접종하고 배양하여 제조된 제1살충성분 30~70 중량%； 및 작두콩 10~20 중량부, 흰목이버섯 2~5 중량부, 및 삼지구엽초 5~10 중량부에 물 300~600 중량부를 가하여 열수추출 및 농축하고, 상기 농축액에 바실러스 섭틸리스(Bacillus subtilis)균주를 3~5 중량부를 접종하고 배양하여 제조된 제2살충성분 30~70 중량%；를 포함하는 천연 살충제 조성물 및 그의 제조방법을 제공한다.
