Objective Since the traditional single-sensor acquisition for the apex-cardiogram (ACG) signal is not easy to determine the sensor location and the reliability of the ACG signal is uncertain, we proposes a new method for the ACG signal acquisition. Methods With the sensor array design, three identical piezoelectric sensors are designed as a fixed equilateral triangular structure which can collect three ACG signals synchronously. Meanwhile, the amplitude and frequency attenuation characteristics are analyzed in the transmission process of the ACG signal. Then the hyperbolic position model is established and the true ACG signal is constructed based on this model. Finally, we collect the three ACG signals from 20 subjects and extract three feature points (C, E and O point) for each ACG signal. For each subject, the feature points of sensor A is set to be the reference location. Then the feature point location deviations of sensor B and C from reference location are analyzed. Results The t test shows that the deviations of sensor B and C are statistically significant, suggesting that the ACG signal is vulnerable to the sensor position and the reliability of single-sensor ACG signal is not high. Conclusions This paper proposes a new method for ACG signal acquisition to solve the difficult position choice problem for the single-sensor and the hyperbolic position model is used to construct the more reliable ACG signals.