Ha was born in Hong Kong, and started learning Catholic catechism and was then baptised during his study in secondary school.

After his graduation, he worked in the field of banking[2] before finding his vocational calling after a pilgrimage to a Marian shrine.

On 11 July 2014, Ha was appointed as one of the three auxiliary bishops of Hong Kong by Pope Francis, holding the titular see of Simitthu, along with Michael Yeung Ming-cheung and Stephen Lee Bun-sang.

Then, we would be in a better position to help fellow Hongkongers.”[10] The coat of arms of Bishop Ha is unique in two ways: it adopted a simpler design of tassel cord loop, symbolizing simplicity, straightforwardness and sincerity; and it uses a Franciscan cross, instead of the more common Latin Cross, behind the shield.

His episcopal motto is Pax et Bonum, the greeting of St. Francis of Assisi, meaning peace and goodness.