直接放步骤！很简单

1.首先先登录网页steam账号

2.然后打开https://store.steampowered.com/account/licenses/

3.复制代码，更新地址：https://steamdb.info/freepackages/

(function()
{
	if( location.href.match( /^https:\/\/store\.steampowered\.com\/account\/licenses\/?$/ ) === null )
	{
		alert( 'Please run this on Steam\'s account page details: https://store.steampowered.com/account/licenses/' );

		window.location = 'https://store.steampowered.com/account/licenses/';

		return;
	}
	
	var freePackages =
	[
		 All Zombies Must Die Demo
		21101, //  DiRT Showdown Demo
		21102, //  Rayman Origins Demo
		21103, //  iBomber Defense Pacific  Demo
		21104, //  Men Of War: Assault Squad GOTY Demo
		21105, //  Bang Bang Racing Demo
		21106, //  Sine Mora Demo
		21107, //  Noitu Love 2 Devolution Demo
		21108, //  Waveform Demo
		21109, //  Ridge Racer™ Unbounded Demo
		21110, //  Hegemony Gold: Wars of Ancient Greece
		21111, //  Rocksmith Demo
		21113, //  Binary Domain Demo
		21114, //  Sniper Elite V2 Demo
		21115, //  Blades of Time Demo
		21117, //  A Valley Without Wind Demo
		21118, //  F1 2012 Demo
		21119, //  Magical Diary Demo
		21120, //  The Dream Machine Demo
		21121, //  Hell Yeah! Demo
		21122, //  A Virus Named Tom Demo
		21123, //  Splice Demo
		21124, //  Atooms to Moolecules
		21125, //  BeatBuddy Demo
		21126, //  DIVO
		21127, //  Imagine Earth Demo
		21128, //  MilitAnt
		21129, //  Plutonic Repulse
		21130, //  The White Laboratory Demo
		21131, //  Blackwell's Asylum
		21132, //  Magic 2014 Demo
		21133, //  Sid Meier's Civilization V: Gods & Kings Demo
		21134, //  Gratuitous Tank Battles Demo
		21135, //  Tiny and Big: Grandpa's Leftovers Demo
		21136, //  KungFu Strike Demo
		21137, //  Adventures of Shuggy Demo
		21138, //  E.Y.E: Divine Cybermancy Demo
		21139, //  Orcs Must Die! 2 Demo
		21140, //  The Book of Unwritten Tales Demo
		21141, //  Sleeping Dogs™ Demo
		21142, //  Damage Inc Demo
		21143, //  Gateways Demo
		21144, //  Football Manager 2013 Demo
		21145, //  XCOM: Enemy Unknown Demo
		21146, //  Transcripted Demo
		21147, //  Intrusion 2 Demo
		21148, //  Din's Curse Demo
		21149, //  Democracy 2 Demo
		21150, //  Ys Origin Demo
		21151, //  Ether Vapor Remaster Demo
	];
	
	var ownedPackages = {};
	
	jQuery( '.account_table a' ).each( function( i, el )
	{
		var match = el.href.match( /javascript:RemoveFreeLicense\( ([0-9]+), '/ );
		
		if( match !== null )
		{
			ownedPackages[ +match[ 1 ] ] = true;
		}
	} );
	
	var i = 0,
	    loaded = 0,
	    package = 0,
	    total = freePackages.length,
	    modal = ShowBlockingWaitDialog( 'Executing…',
	    	'Please wait until all requests finish. Ignore all the errors, let it finish.' );
	
	for( ; i < total; i++ )
	{
		package = freePackages[ i ];
		
		if( ownedPackages[ package ] )
		{
			loaded++;
			continue;
		}
		
		jQuery.post(
			'//store.steampowered.com/checkout/addfreelicense',
			{
				action: 'add_to_cart',
				sessionid: g_sessionID,
				subid: package
			}
		).always( function( )
			{
				loaded++;
				
				modal.Dismiss();
				
				if( loaded >= total )
				{
					location.reload();
				}
				else
				{
					modal = ShowBlockingWaitDialog( 'Executing…',
						'Loaded <b>' + loaded + '</b>/' + total + '.' );
				}
			}
		);
	}
}());

4.在浏览器右键点击审查元素或者（检查）找到Console->粘贴代码->回车键执行->喜加N

可以看到，获取了一堆游戏大概有70多个