Objective To evaluate the biosafety of a nano-silver modified porcine small intestinal submucosa (NS-PSIS) mesh. Methods To prepare the porcine small intestinal submucosa (PSIS) biological materials, the mucosa and muscle layers were removed from fresh porcine small intestine by mechanical method and SDS method. 50 μg/mL monomer nano-silver (15 nm in diameter) solution was prepared and the PSIS was exposed to the solution to prepare NS-PSIS. The biological safety of our self-made nanometer silver biological material was examined by pyrogen test, skin irritation test, skin stimulus test, acute systemic toxicity test and the metabolism of silver absorption test. Results The prepared NS-PSIS mesh was not pyrogenic and had no skin, subcutaneous irritation or systemic acute toxicity. Flame atomic absorption spectrophotometry results showed that NS-PSIS mesh caused no silver deposit in major organs such as the brain, blood, liver or kidney of SD rats. Conclusion Our nano-silver modified small intestinal submucosa mesh has satisfactory biosafety.