The analysis estimates that 3.1 children with working parents will be living in poverty this financial year (2018/19), compared with 2.1 million in 2010.
It adds that children with at least one working parent will account for two thirds of all children living in poverty in 2018.
The TUC says that pay freezes and in work benefit cuts are the key factors for the rise.
"Child poverty in working households has shot up since 2010," said TUC general secretary Frances O'Grady.
"Years of falling incomes and benefit cuts have had a terrible human cost. Millions of parents are struggling to feed and clothe their children. The government is in denial about how many working families just can't make ends meet."
She called on the government to increase the minimum wage and overhaul the benefits system to lift working families out of poverty.
"We need ministers to boost the minimum wage now, and use the social security system to make sure no child grows up in a family struggling to get by," she added.
The analysis also says that families where both parents work in the public sector have been hit hardest, with their average household income falling by £83 a week in real terms since 2010.
Households where one parent works in the public sector and another works in the private sector have lost £53 a week on average, while private sector workers have seen their income fall by £32 a week, claims the analysis.
It also says that the East Midlands has been the worst hit region, with child poverty among working families rising by 76 per cent since 2010. The next largest rise is in the West Midlands (66 per cent) and Northern Ireland (60 per cent).
The TUC analysis has been carried out by Landman Economics and defines poverty as having an income of less than 60 per cent of the median average income after housing costs.
The Department for Work and Pensions has been contacted for comment.
