Recently, the Ministry of Public Security promulgated the "standards of control tool", classes the knive three kinds, the Ministry of Public Security also provides that No matter what kind of knives, everyone has to get permits before they can wear, production and sale of knives,even at home, placing tool, but also unlawful. This "standards of control tool," bringing knives into three categories: The first category is a two-edged dagger with a single blood groove, Tri-knife with a self-locking device flick-knives, jump knife, this type has the strongest destruction, and the remaining two were in line with the tip of the knife tough angle and the length of distinction. As the knives have destruction , the public security department provide,it is only through the relevant permit conditions,People can wear, produce and sale, or else These tools must not bring into public places and use of public transport, even at his home , also constitutes an offense.