The embodiment of the invention provides a method and a device for detecting multiple emission signals, which are is applied to solving the problems of high computational complexity or relatively large storage space is required when detecting multiple emission signals. The method comprises the steps that: signals which comprising multiple emission signals, channel alluvial response and white noise are received; the signals received are carried out space time matched filtering treatment to obtain sufficient statistics y of the signals received and a channel correlation matrix H is obtained according to the sufficient statistics y and a channel model; with respect to the y, H is in Krylov subspace to calculate multi emission signals. The embodiment of the invention can reduce computational complexity by calculating in the Krylov subspace.