方法一：
用UIWebView就可以了
-(void)loadDocument:(NSString*)documentName inView:(UIWebView*)webView
{
    NSString *path = [[NSBundle mainBundle] pathForResource:documentName ofType:nil];
    NSURL *url = [NSURL fileURLWithPath:path];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    [webView loadRequest:request];
}

// Calling -loadDocument:inView:
[self loadDocument:@"test.doc" inView:self.myWebview];


方法我也已经测试过了，希望对大家有帮助，


方法二：
下面方法是直接通过QLPreviewController打开文档

qlViewController = [[QLPreviewController alloc] init];
   qlViewController.dataSource = self;  
   [self presentModalViewController:qlViewController animated:YES];


- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller {
return 1;
}
- (id <QLPreviewItem>)previewController:(QLPreviewController *)controller 
      previewItemAtIndex:(NSInteger)index{
//-------------读文件
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
if (!documentsDirectory) {
  NSLog(@"Documents directory not found!");//return ;
} 
NSString *fileName=[NSString stringWithFormat:@"%@.%@",nameQ,extQ];
NSString *appFile = [documentsDirectory stringByAppendingPathComponent:fileName]; 
//-------------
NSURL *myQLDocument = [NSURL fileURLWithPath:appFile];
return myQLDocument;
}