These three are almost the same. They are all mean "to give (financial) support". 但是有subtle 不一样。 「补助」是 the support any other people or institute give you when you wanna do something. 比如说(for example)：我得到奖学金「补助」which means I won a scholorship to support me (studying abroad); that is, you wanna study abroad, and somebody to give you "scholarship" this kind of 「补助」。 而「津贴」is sort of support come from 政府 或 公司。It is quite formal that we barely use in everyday conversations. when 「津贴」 comes from 政府，It usually means the support giving to relatively underrepresented people, like farmer in developed country. 比如说：因为我是农人，我每年可以得到来自政府的社会「津贴」。(coz i am a farmer, i get subsidization every year from the government) And when it comes to 公司，it means the additional payment giving to one who does additional tasks outside his initial job or one who face risks while performing your job. 比如说：因为我的工作比较危险，所以我有 额外的 保健「津贴」。(coz my job is dangerous, I got additional medical subsidy.) 至于「补贴」has two different meaning. One of which is formal and refer to the support given by政府 in order to reduce the price of a certain necessary commodity . 比如说：为了不使米价继续升高，政府给予经济上的「补贴」。(to avoid the price of rice climbing, the government offer some economic subsidy.) And the other one is relatively informal which refers to the financial support you give to the one who was hurt by you. It is like "compensation"

补贴一般是区域性或者行业性的，就是某个地区或某个行业整体都有。 补助一般就是对个别事项、个别人的补偿，比如通讯补助，交通补助。 津贴为了补偿职工特殊或额外的劳动消耗和因其他特殊原因支付给职工的福利。