Abstract: A phased array acoustic logging method was proposed to address the accuracy issue of measuring formation compressional wave velocity in cases where poor bonding exists between the formation and casing. This method utilizes adjacent receiver transducers to suppress casing waves and enhance formation waves by adjusting their phase relationship. In brief, a phase control circuit is added to the signal conditioning module of the acquisition circuit to achieve signal phase delay and amplitude adjustment, such that adjacent transducers receive casing waves with identical arrival times and amplitudes, which cancel each other out through superposition. To validate the effectiveness of this method, a phase-shift circuit was designed and experiments were conducted in a laboratory free-casing model well. The results showed that the use of this method effectively suppressed casing waves and enabled clear identification of formation compressional waves, thus verifying its feasibility.