This invention is an alimentary tract emptying function detection slow release pill and its preparation technique, and it includes framework core and coating. Materials of coating are medical use paraffin wax or silicon rubber, its thickness is 0.1mm - 1.5mm, via holes on coating is connected to framework core in coating. Cross sectional area of each hole is 0.1-10mm², framework core length is 5-40mm, width is 5-15mm. its preparation technique mainly includes following procedures: providing framework core materials, and preparing framework core, coating liquor, and making coating, via holes. This product can be used to detect security of alimentary canel swallow electronic capsule, and its using is convenient, and security and reliability is high.