Newton's law of universal gravitation does not explain Mercury's orbit anomalous precession, and gravitational constant G values measured by different research teams do not coincide. This paper studied universal gravitation from a physical aesthetics and ideal fluid perspective, derived new formula for calculating the exact G value by using the speed of light in vacuum with formulas for error correction, and verified by experimental results of other scientists. This provides another explanation for Mercury's anomalous precession, which is completely different from Einstein's general relativity. Conclusion is that G equals 1/(16πc) and Mercury's anomalous precession equals 43"/cy should not be the evidence for prove Einstein's general relativity is correct. In addition, an experimental plan is proposed for the space agency to further verify who is right.