The invention discloses a gait-electrocardiogram (ECG) RR interval correlation method based on Gaussian regression. The invention comprises the following steps: step 1, synchronously acquiring three-dimensional coordinate data of motions of a subject and corresponding ECG signals by using a three-dimensional motion tracking system and an ECG acquisition device, respectively; step 2, carrying out gait quantitative analysis, nonlinear analysis and time-frequency analysis on the three-dimensional coordinate data, extracting 17 features to form a feature vector, and providing a fusion method; step 3, pre-processing the ECG signals to extract RR intervals; step 4, constructing a Gaussian process regression (GPR) correlation prediction model between the gait features and the ECG RR intervals; and 5, training and testing the GPR model, and performing correlation prediction analysis. The invention has advantages of strong self-adaptation, easiness in realization, super-parameter self-adaptive acquisition, etc., has better robustness and generalization performance, and can better reveal correlation information between the gait and the ECG.