The invention discloses a device and method for detecting the solution loss initial temperature and solution speed of coke. The device comprises temperature control equipment, a coke reaction device, a computer processing unit, a carbon dioxide gas washer, a gas flow controller and a carbon monoxide concentration online detector; the carbon dioxide gas washer, the gas flow controller, the coke reaction device and the carbon monoxide concentration online detector are sequentially connected; the temperature control equipment is connected with the coke reaction device and used for controlling the temperature of the coke reaction device; the computer controlling and processing unit is connected with the temperature control equipment and the carbon monoxide concentration online detector and is used for acquiring and processing temperature and concentration information. The device is obtained by transformation on the basis of a coke reactivity detection device and a coke post-reaction strength detection device commonly used in an iron and steel enterprise; according to the device disclosed by the invention, no new equipment needs to be purchased, the cost is reduced and the device can be reused.