IOS上传多个图片数据，当传到第5张的时候开始提示这个错误，求助啊

errorInfo_testDataDownloadWithProgress:NSURLErrorDomain -----1003------{
    NSErrorFailingURLKey = "http://159cloud.oss-cn-qingdao.aliyuncs.com/EDB95E4C-F6D4-4BD8-A701-1D05AC916F52";
    NSErrorFailingURLStringKey = "http://159cloud.oss-cn-qingdao.aliyuncs.com/EDB95E4C-F6D4-4BD8-A701-1D05AC916F52";
    NSLocalizedDescription = "\U672a\U80fd\U627e\U5230\U4f7f\U7528\U6307\U5b9a\U4e3b\U673a\U540d\U7684\U670d\U52a1\U5668\U3002";
    NSUnderlyingError = "Error Domain=kCFErrorDomainCFNetwork Code=-1003 \"\U672a\U80fd\U627e\U5230\U4f7f\U7528\U6307\U5b9a\U4e3b\U673a\U540d\U7684\U670d\U52a1\U5668\U3002\" UserInfo=0x1240a5a0 {_kCFStreamErrorCodeKey=-72000, NSErrorFailingURLStringKey=http://159cloud.oss-cn-qingdao.aliyuncs.com/EDB95E4C-F6D4-4BD8-A701-1D05AC916F52, NSErrorFailingURLKey=http://159cloud.oss-cn-qingdao.aliyuncs.com/EDB95E4C-F6D4-4BD8-A701-1D05AC916F52, NSLocalizedDescription=\U672a\U80fd\U627e\U5230\U4f7f\U7528\U6307\U5b9a\U4e3b\U673a\U540d\U7684\U670d\U52a1\U5668\U3002, _kCFStreamErrorDomainKey=10}";
    "_kCFStreamErrorCodeKey" = "-72000";
    "_kCFStreamErrorDomainKey" = 10;
}