两个词在意思上有差别的。
reveal v. 揭示，揭露
〔辨析〕
指揭露此前不为人知或隐秘的事，常可与 disclose 换用。
〔例证〕
She will never reveal/disclose her friends' secrets.
她绝不会泄露朋友的秘密。
Details of the murder were revealed/disclosed by a local newspaper.
一家地方报纸披露了谋杀的细节。
show v. 显现，显出
〔辨析〕
语气较强，强调明显地表现出来。
〔例证〕
Her worry showed in her eyes.
她的眼神显露出忧愁。
Spain's economy began to show signs of recovery.
西班牙的经济开始显露出复苏的迹象。