打击犯罪，捍卫法律威严，保护一方平安是刑警的职责，代号为803的中国刑警，在日常工作中，侦破了很多要案，得以被记录下来。刑侦总队队长陈雷（张垒 饰），办案经验丰富，善于捕捉细节、遇事沉着冷静，是优秀的刑事警察。女警员周扬（董维嘉 饰），大胆果断，思维敏捷，即使面对危险重重的缉凶行动也丝毫不畏惧。陆姐（陆玲 饰）是技术侦查的骨干，业务娴熟，证物是每个案件的眼镜，因此陆姐的工作对案件侦破起到了决定性的作用。杨伟业（韩含 饰）因为遭遇青梅竹马的女友出轨，心理逐渐扭曲，视人命如草芥，制造了一系列惨案。法网恢恢，最终难逃法律制裁

Fighting crime, defending the majesty of the law, and protecting the safety of one party are the duties of the criminal police. The Chinese criminal police, code-named 803, have solved many important cases in their daily work , was recorded. Chen Lei (played by Zhang Lei), the captain of the criminal investigation team, has rich experience in handling cases, is good at capturing details, and is calm and calm in situations. He is an excellent criminal policeman. Female police officer Zhou Yang (played by Dong Weijia), bold and decisive, with quick thinking, is not afraid even in the face of dangerous hunting operations. Sister Lu (played by Lu Ling) is the backbone of technical investigation, skilled in business, and the evidence is the glasses of every case. Therefore, Sister Lu's work has played a decisive role in the detection of the case. Yang Weiye (played by Han Han) was gradually distorted because of his childhood sweetheart girlfriend's derailment, and he regarded life as nothing, causing a series of tragedies. The legal net is restored, and it is impossible to escape legal sanctions in the end