Stipulations in Technical Specification for Vacuum Preloading Technique to Improve Soft Soils (JTS 147—2009) concerning the time of heaped load of vacuum combined surcharge preloading, the layout, flow capacity and type of the filter tube, settlement calculation, as well as the standard of detection and unloading are relatively vague. Based on previous experience in the design and comparing with relevant specifications, we carry out the computational analysis about all the questions above and propose recommendations. It is suggested to determine the time of unloading based on the test data.