Wlodarczyk threw 82.98m to surpass the 82.29m record she set when winning gold at the Rio Olympics earlier this month.
The 31-year-old is the only woman in history to throw over 80 metres and has achieved that feat 11 times, including three times at Sunday's meet in Poland.
Wlodarczyk's new world record is yet to be ratified.
Poland's Olympic champion Anita Wlodarczyk has broken her own hammer world record at the Kamila Skolimowska Memorial in Warsaw.