The invention relates to a generalized subspace tracing-based time-varying structure mode parameter identification method. The method comprises the following steps of: firstly measuring a
vibration response of a structure with a time-varying characteristic, constructing a multi-dimensional time
delay vector according to
vibration response monitoring data, calculating a related function matrix of the vector, and initializing a generalized subspace tracing
algorithm by adoption of feature value
decomposition; secondly, carrying out online updating on the related function matrix of the multi-dimensional time
delay vector according to new
vibration response monitoring data through importing a
forgetting factor, and carrying out online updating on an
orthogonal matrix pion (k) by adoption of the generalized subspace tracing
algorithm; and finally, calculating a discrete
state space matrix and an
observation matrix at any moment according to the updated
orthogonal matrix pion (k), carrying out feature value analysis on the discrete
state space matrix, and extracting mode parameters such as a mode frequency, a
damping ratio and a vibration mode of the structure. The method is suitable foridentifying mode parameters of time-varying structures in a plurality of fields, and is simple and convenient to use, high in calculation precision, strong in robustness and high in calculation efficiency.