Abstract: Disclosed are a sphere decoding detection method and apparatus, including: preprocessing a received signal to obtain a signal approximate estimation value Xpre of the received signal, deducing an initial square radius D2 of sphere decoding detection according to Xpre, and determining the size I of a constellation space according to the current signal to noise ratio of the received signal; according to depth first and sphere constraint rules, searching for a search path depending on the size I of the constellation space and an initial square radius D2; after a search path is searched out, and when the sum of local Euclidean distances of the searched-out search path is less than the current square radius, updating the square radius, and re-searching for a search path until a search path cannot be searched out, and determining a candidate signal point corresponding to the latest saved search path as the optimum signal estimation point.