The invention discloses a method and a device for indicating and determining a downlink control information format. The method comprises the following steps of when the
bit length of the downlink control information within a short
transmission time interval is the same as the
bit length of the downlink control information within a traditional
subframe, carrying an indication in the
information field, and indicating that the downlink control information is the downlink control information of the traditional
subframe or the downlink control information of the short
transmission time interval; after receiving the downlink control information, determining whether the downlink control information is the downlink control information of the traditional
subframe or the downlink control informationof the short
transmission time interval according to the indication. By adopting the technical scheme of the invention, the downlink control information of the traditional subframe and the downlink control information of the short
transmission time interval, which are the same in size, can be distinguished from each other by the terminal. Therefore, the times of blind detection for the terminal during the transmission of the short downlink control information in a traditional
control area can be reduced.