+ (NetWorkType)currentNetworkType{
    
    Reachability *reachability   = [Reachability reachabilityWithHostName:@"www.apple.com"];
    NetworkStatus internetStatus = [reachability currentReachabilityStatus];
   
    NetWorkType net = NetWorkTypeNone;
    switch (internetStatus) {
        case ReachableViaWiFi:
            net = NetWorkTypeWiFI;
            break;
            
        case ReachableViaWWAN:
            net = NetWorkType4G;
//            net = [self getNetType];   //判断具体类型
            break;
            
        case NotReachable:
            net = NetWorkTypeNone;
            
        default:
            break;
    }
    
    return net;
    
}

+ (NSString *)getNetType
{
    CTTelephonyNetworkInfo *info = [[CTTelephonyNetworkInfo alloc] init];
    NSString *currentStatus = info.currentRadioAccessTechnology;
    NSString *netconnType;
    if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyGPRS"]) {
        netconnType = @"GPRS";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyEdge"]) {
        netconnType = @"2.75G EDGE";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyWCDMA"]){
        netconnType = @"3G";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyHSDPA"]){
        netconnType = @"3.5G HSDPA";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyHSUPA"]){
        netconnType = @"3.5G HSUPA";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMA1x"]){
        netconnType = @"2G";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMAEVDORev0"]){
        netconnType = @"3G";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMAEVDORevA"]){
        netconnType = @"3G";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMAEVDORevB"]){
        netconnType = @"3G";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyeHRPD"]){
        netconnType = @"HRPD";
    }else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyLTE"]){
        netconnType = @"4G";
    }
    return netconnType;
}

Demo：https://github.com/genghongkai/GetNetworkStatus.git