Objective:To observe the clinical efficacy of B ultrasound-guided large-channel percutaneous nephrolithotomy(PCNL)in recumbent-supine position for treating kidney staghorn stone.Method:From July 2015 to August 2016,200 patients with kidney staghorn stone admitted into our hospital were randomly divided into control group(n=100)and research group(n=100).Control group was treated with middle-,small-channel PCNL in traditional prone position,while research group was treated with B ultrasound-guided large-chann...