Weak signal detection is very important for the downhole acoustic telemetry system used in the process of petroleum exploration and development. This paper introduces a new method of weak signal detection which based on LabVIEW Programming for the downhole acoustic telemetry systems. First, analyzed the signal transmission characteristics and noise distribution law, as well as weak signal detection principle, and then on this basis, proposed an effective intelligent time-frequency Joint detection method which achieved by LabVIEW Programming, conducted a detailed analysis for how the different parameters impacted the system states and an actual signal detection experiment. The results show that the method in detecting characteristic parameters of the weak signal and improving the signal to noise ratio is a very effective way, the method could effectively detect the desired signal under strong noise background. It could meet the needs of acoustic telemetry system.