A high-frequency signal sampling approach by combining with compressive sensing and random equivalent sampling technology is proposed. The proposed sampling method achieves ∼10 times faster equivalent sampling rate by utilizing three parallel sub-Nyquist low-rate analog-to-digital converters (TPSL-ADC). By the union of the optical electric-field sensor with wide dynamic range and the proposed TPSL-ADC sampling method, a complete high-frequency electric-field signal measurement system has been realized. The high-frequency electric-field signal with an equivalent sampling rate of 1  GS  /  s is captured by utilizing three parallel ADCs with sampling rates of ∼32.3, 31.3, and 30.3  MS  /  s, respectively. The effectiveness of the proposed electric-field sensing and detecting system has been experimentally demonstrated.