In order to study the influence of temperature on the coda wave signal of concrete ultrasonic test, the normalized angle between signal vectors is used as the fluctuation index to reflect the signal change caused by temperature effect. The eigenvectors characterising the magnitude of the temperature effect are obtained by SVD of the vector residual matrix, and the mathematical relationship between the vector space mapping and the temperature difference is established. Verification of concrete beam code wave signals are collected in the laboratory. The results show that the waveform of the coda wave signal shifts backward with increasing temperature, and the proposed method can quantify the temperature effect piecewise and linearly. Based on the quantization results, the most sensitive temperature range of ultrasonic coda wave signal at room temperature is obtained. When the temperature span is 4.5 ℃, 74%~90% of the temperature effect can be removed.