被父母视为小太阳的独生子女丁放和伙伴们偶然得到一条叫“宝贝儿”的狗，没想到遛狗时把祸闯到了孤独的盲老人梁爷爷的院子里。遭到父亲打骂的丁放离家出走，无意中了解到老人的孤独和苦闷。大受震动的丁放和伙伴们决定把自己心爱的“宝贝儿”驯成“导盲犬”，帮助梁爷爷。在驯狗、送狗与梁爷爷和解的过程中，丁放和小伙伴们成长了，终于明白，要想成为真正的小太阳，就要放光放热无私地付出。

Ding Fang, the only child of his parents, is regarded as the little sun, centre of the family. He gets by chance with his playmates a pet dog called Puppy. However, the dog makes trouble in a blind and lonely old man, Grandpa Liang’s yard when it is taken out for a walk. Ding Fang is punished by his father and decides to leave home. He happens to understand the solitude and helplessness of Grandpa Liang. Out of shock and compassion, he and his playmates decide to train Puppy into a guide dog to help Grandpa Liang. In the course of training, sending the dog to Grandpa Liang and getting along with him, Ding Fang and his playmates grow up and realize that the real little sun should give out light and heat selflessly.